Development of a whole-cell biosensor for detecting organophosphorus pesticide methyl parathion in the farmland soil / 生物工程学报

The evaluation of the bioavailability of pollutants in soil is crucial to accurately assess the pollution risk, and whole-cell biosensor is one of the important tools for such evaluation. This study aimed to develop a novel whole-cell biosensor for the detection of methyl parathion in soil using. First, a whole-cell biosensor was constructed by the screened methyl parathion hydrolase mpd gene, the existing specific induction element pobR, and the pUC19 plasmid skeleton. Then, the detection method of methyl parathion in soil extracts was established using 96-well microtiter plate as carrier and five whole-cell biosensors as indicator. The method was applied in the detection of methyl parathion in tested and field soil extracts. Taking E. coli DH5α/pMP-AmilCP with the best detection performance as an example, this biosensor had a detection limit of 6.21-6.66 µg/L and a linear range of 10-10 000 µg/L for methyl parathion in four soil extracts. E. coli DH5α/pMP-RFP and E. coli DH5α/pMP-AmilCP methods have good detection performance for the analysis of methyl parathion in soil extract samples. This biosensor method can help to quickly assess the bioavailability of methyl parathion in soil, and thus help to understand the risk of soil pollution caused by organophosphorus pesticide methyl parathion.

AGAR / CHITOSAN BLENDS FOR THE PREPARATION OF NOVEL HYDROGELS FOR PH SENSING, UREA ADSORPTION AND DYE ADSORPTION

Hydrogel posses a degree of flexibility very similar to natural tissues, due to their significant water content. Thus they find potential biomedical applications owing to their excellent bio-compatibility, bio degradability and non toxicity. The main highlight of the work is that it is taking naturally occurring polymers such as agar and Chitosan for the synthesis of hydrogel. Different compositions of Chitosan/Agar hydrogels were formulated and optimised with respect to pH sensing, Urea absorption and dye adsorption. Chitosan/Agar hydrogels are found to be suitable and a potential candidate for several agricultural and bio medical applications

Interações populacionais mediadas por quorum sensing na microbiota do soro-fermento utilizado na produção do queijo Canastra / Population interactions mediated by quorum sensing in the microbiota of the endogenous culture used in the production of canasta cheese

Bactérias regulam a expressão de diversos fenótipos de acordo com a sua densidade populacional, em um comportamento conhecido como quorum sensing. Em micro-organismos de origem alimentar, o quorum sensing pode influenciar na formação de biofilmes, produção de toxinas e de enzimas hidrolíticas. Em bactérias Gram-negativas a sinalização é normalmente mediada por moléculas de N-acilhomoserina lactona (AHLs), conhecidas por autoindutor 1 (AI-1). Estudos revelam a inibição do quorum sensing nestas bactérias por enzimas que degradam as AHLS, em um processo denominado quorum quenching. Tipicamente brasileiro, o queijo Canastra é um produto artesanal maturado, produzido a partir de leite cru e do pingo, um tipo de soro-fermento coletado e utilizado diariamente na produção. A composição microbiana do pingo é diversificada e característica da região produtora. Essa combinação de bactérias, única em cada queijaria, resulta em aroma e textura típicos. Enquanto a microbiota Gram-positiva contribui para o desenvolvimento de sabor, textura e aroma no produto, bactérias Gram-negativas nesses queijos são geralmente associadas à formação de olhaduras, aromas desagradáveis, má coagulação da massa e até à patogenicidade. Este trabalho visou analisar a interação entre a microbiota Gram-positiva e Gram-negativa presente no pingo pela detecção dos sistemas de quorum sensing e quorum quenching nas amostras. A presença de AHLs foi avaliada em 45 amostras de pingo, a partir da extração em acetato de etila acidificado e da avaliação dos extratos por meio de bioensaios com Agrobacterium tumefaciens WCF47(pCF218)(pCF372) e KYC55(pJZ410)(pJZ372)(pJZ384), resultando em apenas uma amostra positiva. Em seguida, 350 isolados foram obtidos a partir de 11 amostras de pingo, sendo 200 isolados classificados como Gram-positivos e 150 Gram-negativos. Os Gramnegativos foram avaliados quanto à produção de AHLs in vitro através de ensaio em placa utilizando as estirpes biossensoras A. tumefaciens WCF47(pCF218)(pCF372), Chromobacterium violaceum CV026 e Escherichia coli pSB403, resultando em 39 isolados produtores de AHLs, provenientes de 10 pingos diferentes. Já os isolados Gram-positivos foram analisados quanto à capacidade de inibição do QS utilizando as estirpes biossensoras C. violaceum CV026 e A. tumefaciens WCF47(pCF218)(pCF372), em meio suplementado com C6-HSL ou 3-oxo-C12-HSL. Foi detectada a inibição total da resposta ao quórum por 78 isolados testados, enquanto a inibição parcial foi provocada por outros 63. A inibição do crescimento das estirpes biossensoras também foi observada para 24 isolados. Os isolados promotores de inibição parcial foram recultivados em meio mínimo com C6-HSL ou 3-oxo-C12-HSL como únicas fontes de carbono. Foram recuperados 28 isolados, e a ação desses sobre diferentes substratos foi avaliada, resultando em 22 isolados produtores de lactonases e 6 produtores de acilase. Os 39 isolados Gram-negativos e os 28 isolados Gram-positivos finais foram identificados por MALDI-TOF MS, resultando, segundo o conhecimento do autor, no primeiro relato de produção de AHLs por Pseudomonas fulva, Enterobacter xiangfangensis e Lelliottia amnigena, bem como a produção de lactonases por Staphylococcus xylosus e a produção de acilase por S. aureus, Microbacterium maritypicum e Rothia kristinae. Este trabalho mostrou que interações populacionais mediadas por quorum sensing dependente de AHLs na microbiota do soro-fermento são possíveis. Porém, essas interações estão propensas a serem inibidas por meio de lactonases e acilases produzidas por parte das bactérias Gram-positivas

Bacteria regulate the expression of different phenotypes according to their population density, in a behavior known as quorum sensing. In food-borne microorganisms, quorum sensing can influence the formation of biofilms, production of toxins and hydrolytic enzymes. In Gram-negative bacteria, signaling is normally mediated by Nacyl homoserine lactone molecules (AHLs), known as autoinducer 1 (AI-1). Studies reveal the inhibition of quorum sensing in these bacteria by enzymes that degrade AHLS, in a process called quorum quenching. Typically Brazilian, Canastra cheese is a matured artisanal product, produced from raw milk and pingo, a type of endogenous culture collected and used daily in production. The microbial composition of pingo is diverse and characteristic of the producing region. This combination of bacteria, unique in each cheese factory, results in a typical aroma and texture. While the Gram-positive microbiota contributes to the development of flavor, texture and aroma in the product, Gram-negative bacteria in these cheeses are generally associated with the formation of eyes, off-flavors, poor curd coagulation and even pathogenicity. Thus, this work aimed to analyze the interaction between the Gram-positive and Gram-negative microbiota present in this culture by detecting quorum sensing and quorum quenching systems in the samples. The presence of AHLs was evaluated in 45 samples of pingo, with extraction with acidified ethyl acetate and the evaluation of the extracts through bioassays with Agrobacterium tumefaciens WCF47(pCF218)(pCF372) and KYC55(pJZ410)(pJZ372)(pJZ384 ), resulting in only one positive sample. Then, 350 isolates were obtained from 11 endogenous culture samples, with 200 being classified as Gram-positive and 150 Gram-negative. Gram-negatives were evaluated for the production of AHLs in vitro by plaque assay using the biosensor strains A. tumefaciens WCF47(pCF218)(pCF372), Chromobacterium violaceum CV026 and Escherichia coli pSB403, resulting in 39 AHL-producing isolates from 10 different samples. Gram-positive isolates were analyzed for their ability to inhibit quorum sensing using biosensor strains C. violaceum CV026 and A. tumefaciens WCF47(pCF218)(pCF372), in medium supplemented with N-hexanoyl-L-homoserine lactone or 3-oxo-dodecanoyl-Lhomoserine lactone. Total inhibition of the quorum response was detected by 78 tested isolates, while partial inhibition was caused by 63. Growth inhibition of biosensor strains was also observed for 24 isolates. Partial inhibition promoter isolates were recultured on minimal medium with C6-HSL or 3-oxo-C12-HSL as sole carbon sources. Twenty-eight isolates were recovered, and the action of these isolates on different substrates was evaluated, resulting in 22 lactonase producers and 6 acylase producers. The 39 Gram-negative isolates and the final 28 Grampositive isolates were identified by MALDI-TOF MS, resulting, to the best of the author's knowledge, in the first report of AHL production by Pseudomonas fulva, Enterobacter xiangfangensis and Lelliottia amnigena, as well as the lactonase production by Staphylococcus xylosus and acylase production by S. aureus, Microbacterium maritypicum and Rothia kristinae. This work demonstrated that population interactions mediated by AHLs-dependent quorum sensing in Canastra cheese endogenous culture microbiota are possible. However, these interactions are prone to inhibition by lactonases and acylases produced by Gram-positive bacteria

Application and development of molecular diagnostic techniques for detection infectious diseases / 中华检验医学杂志

With the development of the concept of precision medicine, under the background of the new coronavirus pneumonia epidemic, the clinical diagnosis and treatment of infectious diseases has received more and more attention. The experimental diagnosis technology with molecular biology as the core is used as important means for the clinical laboratory diagnosis of infectious diseases. This lcind of technology is paid special attention. In recent years, advances in nanomaterials, applied chemistry, photophysics, and biosensing technologies have also ushered in revolutionary and creative developments in molecular diagnostic technology. This article reviews the application and development of the latest molecular diagnostic technologies, such as next-generation quantitative PCR technology and gene sequencing technology, isothermal amplification technology, biochip and biosensor technology in the clinical diagnosis of infectious diseases.

Nucleic acid-based biosensors: analytical devices for prevention, diagnosis and treatment of diseases / Biosensores basados en ácidos nucleicos: dispositivos analíticos para la prevención, el diagnóstico y tratamiento de enfermedades

BACKGROUND: Biosensing techniques have been the subject of exponentially increasing interest due to their performance advantages such as high selectivity and sensitivity, easy operation, low cost, short analysis time, simple sample preparation, and real-time detection. Biosensors have been developed by integrating the unique specificity of biological reactions and the high sensitivity of physical sensors. Therefore, there has been a broad scope of applications for biosensing techniques, and nowadays, they are ubiquitous in different areas of environmental, healthcare, and food safety. Biosensors have been used for environmental studies, detecting and quantifying pollutants in water, air, and soil. Biosensors also showed great potential for developing analytical tools with countless applications in diagnosing, preventing, and treating diseases, mainly by detecting biomarkers. Biosensors as a medical device can identify nucleic acids, proteins, peptides, metabolites, etc.; these analytes may be biomarkers associated with the disease status. Bacterial food contamination is considered a worldwide public health issue; biosensor-based analytical techniques can identify the presence or absence of pathogenic agents in food. OBJECTIVES: The present review aims to establish state-of-the-art, comprising the recent advances in the use of nucleic acid-based biosensors and their novel application for the detection of nucleic acids. Emphasis will be given to the performance characteristics, advantages, and challenges. Additionally, food safety applications of nucleic acid-based biosensors will be discussed. METHODS: Recent research articles related to nucleic acid-based biosensors, biosensors for detecting nucleic acids, biosensors and food safety, and biosensors in environmental monitoring were reviewed. Also, biosensing platforms associated with the clinical diagnosis and food industry were included. RESULTS: It is possible to appreciate that multiple applications of nucleic acid-based biosensors have been reported in the diagnosis, prevention, and treatment of diseases, as well as to identify foodborne pathogenic bacteria. The use of PNA and aptamers opens the possibility of developing new biometric tools with better analytical properties. CONCLUSIONS: Biosensors could be considered the most important tool for preventing, treating, and monitoring diseases that significantly impact human health. The aptamers have advantages as biorecognition elements due to the structural conformation, hybridization capacity, robustness, stability, and lower costs. It is necessary to implement biosensors in situ to identify analytes with high selectivity and lower detection limits

ANTECEDENTES: Las técnicas de biodetección han sido objeto de un interés cada vez mayor debido a ventajas, tales como alta selectividad y sensibilidad, facilidad de manejo, bajo costo, tiempo de análisis corto, preparación sencilla de muestras y detección en tiempo real. Los biosensores se han desarrollado integrando la especificidad única de las reacciones biológicas y la alta sensibilidad de los sensores físicos. Por lo tanto, las técnicas de biodetección han tenido un amplio campo de aplicación y hoy en día son omnipresentes en diferentes áreas del medio ambiente, la salud y la seguridad alimentaria. Se han utilizado biosensores para estudios ambientales, detectando y cuantificando contaminantes en el agua, el aire y el suelo. Los biosensores también mostraron un gran potencial para desarrollar herramientas analíticas con innumerables aplicaciones en el diagnóstico, prevención y tratamiento de enfermedades, principalmente mediante la detección de biomarcadores. Los biosensores como dispositivo médico pueden utilizarse para identificar ácidos nucleicos, proteínas, péptidos, metabolitos, etc. Estos analitos pueden ser biomarcadores asociados al estado de la enfermedad. La contaminación bacteriana de los alimentos se considera un problema de salud pública mundial; se pueden utilizar técnicas analíticas basadas en biosensores para determinar la presencia o ausencia de agentes patógenos en los alimentos. OBJETIVOS: La presente revisión tiene por objeto establecer los últimos adelantos en la utilización de biosensores basados en ácidos nucleicos y su novedosa aplicación para la detección de ácidos nucleicos. Se hará hincapié en las características del desempeño, las ventajas y los desafíos. Además, se examinarán las aplicaciones de los biosensores basados en ácidos nucleicos para la inocuidad de los alimentos. MÉTODOS: Se examinaron artículos de investigación recientes relacionados con los biosensores a base de ácidos nucleicos, los biosensores para la detección de ácidos nucleicos, los biosensores y la inocuidad de los alimentos, y los biosensores para la vigilancia del medio ambiente. También se incluyeron plataformas de biosensores asociadas al diagnóstico clínico y a la industria alimentaria. RESULTADOS: Es posible apreciar que se han reportado múltiples aplicaciones de biosensores basados en ácido nucleico para el diagnóstico, prevención y tratamiento de enfermedades, así como para identificar bacterias patógenas transmitidas por los alimentos. El uso de PNA y aptámeros abre la posibilidad de desarrollar nuevas herramientas biométricas con mejores propiedades analíticas. CONCLUSIONES: Los biosensores pueden ser considerados como los instrumentos más importantes para la prevención, el tratamiento y la vigilancia de las enfermedades que tienen un impacto significativo en la salud humana. Los aptámeros tienen ventajas como elemento de biorreconocimiento debido a la conformación estructural, capacidad de hibridación, robustez, estabilidad y menores costos. Es necesario implementar biosensores in situ para identificar analitos con alta selectividad y menores límites de detección

Perspectivas y aplicaciones reales del grafeno después de 16 años de su descubrimiento / Perspectives and real applications of graphene at 16 years after its breakthrough / Perspectivas e aplicações reais do grafeno após 16 anos de sua descoberta

Resumen A 16 años del gran descubrimiento del grafeno los focos de atención vuelven a estar en este material con el reporte de su comportamiento superconductor dependiendo del apilado de sus capas. Sin embargo, su nombre durante estos últimos años no solo se ha relacionado a la superconductividad, sino que ha sido relacionado con una diversidad muy amplia de aplicaciones, en disciplinas muy diversas, entre las que cabe mencionar: materiales opto-electrónicos, electrodos para catálisis, dispositivos para tratamiento de desechos, biosensores, entre otros. Esto ha hecho que un gran número de grupos de investigación se hayan interesado no solo en estudiar sus propiedades, sino también en investigar nuevos métodos sintéticos que puedan ser escalables a niveles industriales, sin perder sus propiedades electrónicas y mecánicas. A pesar de los numerosos estudios y los recursos invertidos en grafeno no todas las aplicaciones han llegado a ser una realidad, en esta revisión se muestran algunas de las más exitosas.

Abstract 16 years after the great discovery of graphene, the focus and attention are again on this material after the report of its superconducting behavior depending on the stacking of its layers. The graphene has not only been related to superconductivity but has also been related to a wide diversity of applications, in very diverse disciplines. Among them, we can mention: Opto-electronic materials, electrodes for catalysis, devices for waste-water treatment, biosensors, batteries, and solar cells. This has caused a large number of research groups to be interested not only in the study of its properties, but also in the research of new synthetic methods that can be scaled to industrial levels, without losing its electronic and mechanical properties. Despite numerous studies and resources invested in graphene, not all applications have become a reality, some of the most successful are shown in this review.

Resumo 16 anos após a grande descoberta do grafeno, o foco e as atenções voltam a ser neste material com o relato de seu comportamento supercondutor em função do empilhamento de suas camadas. No entanto, seu nome nos últimos anos não tem sido apenas relacionado à supercondutividade, mas tem sido relacionado a uma diversidade muito ampla de aplicações, em disciplinas muito diversas. Entre eles podemos citar: materiais optoeletrônicos, eletrodos para catálise, dispositivos para tratamento de águas residuais, biossensores, baterias e células solares. Isso fez com que um grande número de grupos de pesquisa se interessassem não apenas em estudar suas propriedades, mas muitas pesquisas também foram feitas na geração de métodos sintéticos que pudessem ser dimensionados para níveis industriais, sem perder suas propriedades eletrônicas e mecânicas. Apesar dos inúmeros estudos e recursos investidos em grafeno, nem todas as aplicações se tornaram realidade, algumas das mais bem-sucedidas são apresentadas nesta revisão.

Towards wearable and implantable continuous drug monitoring:A review / 药物分析学报

Continuous drug monitoring is a promising alternative to current therapeutic drug monitoring strategies and has a strong potential to reshape our understanding of pharmacokinetic variability and to improve individualised therapy.This review highlights recent advances in biosensing technologies that support continuous drug monitoring in real time.We focus primarily on aptamer-based biosensors,wearable and implantable devices.Emphasis is given to the approaches employed in constructing biosensors.We pay attention to sensors'biocompatibility,calibration performance,long-term characteristics stability and measurement quality.Last,we discuss the current challenges and issues to be addressed in continuous drug monitoring to make it a promising,future tool for individualised therapy.The ongoing efforts are expected to result in fully integrated implantable drug biosensing technology.Thus,we may anticipate an era of advanced healthcare in which wearable and implantable biochips will automatically adjust drug dosing in response to patient health conditions,thus enabling the management of diseases and enhancing individualised therapy.

Biomarcadores del trastorno del especto autista basados en bioseñales, realidad virtual e inteligencia artificial / Autism spectrum disorder biomarkers based on biosignals, virtual reality and artificial intelligence

Se ha observado que la estratificación de trastornos del espectro autista (TEA) generada por las escalas actuales no es efectiva para la personalización de tratamientos tempranos. La evaluación clínica de TEA requiere su consideración como un continuo de déficits, y existe la necesidad de identificar parámetros biológicamente significativos (biomarcadores) que tengan el poder de caracterizar automáticamente a cada individuo en diferentes etapas del desarrollo neurológico. El incipiente campo de la psiquiatría computacional (CP) intenta satisfacer las necesidades de diagnóstico de precisión mediante el desarrollo de potentes técnicas computacionales y matemáticas. Una creciente actividad científica propone el uso de medidas implícitas basadas en bioseñales para la clasificación de ASD. Las tecnologías de realidad virtual (VR) han demostrado potencial para las intervenciones de TEA, pero la mayoría de los trabajos han utilizado la realidad virtual para el aprendizaje / objetivo de las intervenciones. Muy pocos estudios han utilizado señales biológicas para el registro y el análisis detallado de las respuestas conductuales que se pueden utilizar para monitorear o producir cambios a lo largo del tiempo. En el presente trabajo se introduce el concepto de biomarcadores conductuales basados en VR o VRBB. Los VRBB van a permitir la clasificación de TEA utilizando un paradigma de psiquiatría computacional basado en procesos cerebrales implícitos medidos a través de señales psicofisiológicas y el comportamiento de sujetos expuestos a complejas réplicas de condiciones sociales utilizando interfaces de realidad virtual.

It has been observed that the stratification of Autism Spectrum Disorders (ASD) generated by the current scales is not effective for the personalization of early treatments. The clinical evaluation of ASD requires its consideration as a continuum of deficits, and there is a need to identify biologically significant parameters (biomarkers) that have the power to automatically characterize each individual at different stages of neurological development. The emerging field of computational psychiatry (CP) attempts to meet the needs of precision diagnosis by developing powerful computational and mathematical techniques. A growing scientific activity proposes the use of implicit measures based on biosignals for the classification of ASD. Virtual reality (VR) technologies have demonstrated potential for ASD interventions, but most of the work has used virtual reality for the learning / objective of interventions. Very few studies have used biological signals for recording and detailed analysis of behavioral responses that can be used to monitor or produce changes over time. In this paper the concept of behavioral biomarkers based on VR or VRBB is introduced. VRBB will allow the classification of ASD using a paradigm of computational psychiatry based on implicit brain processes measured through psychophysiological signals and the behavior of subjects exposed to complex replicas of social conditions using virtual reality interfaces.

Aplicaciones biotecnológicas de los microorganismos / Biotechnological applications of microorganisms

Resumen La biodiversidad de los microorganismos así como la naturaleza única y las capacidades biosintéticas en condiciones ambientales específicas hacen que los microorganismos sean los probables candidatos para resolver problemas de escases de alimentos, contro de plagas, biodegradación de los xenobióticos, descomposición de la basura, las pilas de desechos producidas, entre otros. Los microorganismos ofrecen un gran potencial para la exploración de moléculas y procesos, y el conocimiento de las especies no convencionales, especialmente dentro del grupo Archaea, ha estimulado la investigación molecular de genes de interés. Estos nuevos genes pueden incorporarse mediante tecnología recombinante en especies biológicamente conocidas, como E. coli y S. cerevisiae, para la síntesis a gran escala de productos. La microbiología tecnológica tiene grandes potenciales para explorar y obstáculos por superar. Por lo tanto, solo la investigación en esta área resulta prometedora para científicos en todo el mundo. En la presente revisión se presentan las aplicaciones más significativas de los microorganismos en la industria de alimentos, la agricultura, compuestos químicos, combustibles, farmacología y materiales.

Abstract The biodiversity of microorganisms as well as the unique nature and biosynthetic capabilities in specific environmental conditions make microorganisms the likely candidates to solve problems of food shortages, pest control, biodegradation of xenobiotics, decomposition of garbage, batteries of produced waste, among others. Microorganisms offer great potential for the exploration of molecules and processes, and knowledge of non-conventional species, especially within the Archaea group, has stimulated the molecular investigation of genes of interest. These new genes can be incorporated by recombinant technology into biologically known species, such as E. coli and S. cerevisiae, for the large-scale synthesis of products. Technological microbiology has great potentials to explore and obstacles to overcome. Therefore, only research in this area is promising for scientists around the world. In this review we present the most significant applications of microorganisms in the food industry, agriculture, chemical compounds, fuels, pharmacology and materials.

Recent Advances in Biosensors for Nucleic Acid and Exosome Detection / 전남의대학술지

Biosensors are analytical devices for biomolecule detection that compromise three essential components: recognition moiety, transducer, and signal processor. The sensor converts biomolecule recognition to detectable signals, which has been applied in diverse fields such as clinical monitoring, in vitro diagnostics, food industry etc. Based on signal transduction mechanisms, biosensors can be categorized into three major types: optical biosensors, electrochemical biosensors, and mass-based biosensors. Recently, the need for faster, more sensitive detection of biomolecules has compeled researchers to develop various sensing techniques. In this review, the basic structure and sensing principles of biosensors are introduced. Additionally, the review discusses multiple recent works about nucleic acid and exosome sensing.

Research progress of biosensors in the detection of foodborne pathogens / 生物工程学报

As the main factor leading to foodborne illnesses, foodborne pathogens have been attached great importance by people. The development of simple, rapid, high-sensitivity and low-cost food-borne pathogen detection methods is of great significance in reducing the incidence of foodborne diseases. Biosensor technology is a new micro-analysis technology developed by multi-disciplinary cross-infiltration. It has the characteristics of high sensitivity and fast analysis speed, and is widely used in the detection of food-borne pathogens. This paper introduces the basic principles of biosensors, summarizes the application of common biosensors in the detection of foodborne pathogens, and prospects for future development.

Cell-free synthetic biology: an emerging strategy torevolutionize the biomedical industry / 生物工程学报

Cell-free synthetic biology system can perform biological transcription and translation process in vitro. Because of its advanced features, such as flexible openness, easy control, short expression time and high tolerance to cytotoxicity, this systemhas been successfully used to synthesize proteins that are difficult to express in cells. With the continuous development of cell-free biosensing technology and the lyophilization technology, its applications have widely expanded into many biomedical fields. This review discusses the current research progress of cell-free synthetic biology system in on-demand biopharmaceutical synthesis, portable diagnostics, and others. Further development of the system can lead to even more complicated synthesis of therapeutic proteins with post-translational modifications and evolution of different cell-free biosensors with high sensitivity. Cell-free synthetic biology as an emerging engineering strategy can be a better means applied to high-throughput screening of pharmaceutical proteins, detection of new pathogens, and other important health-care fields in the future.

Recent advances in electrogenerated chemiluminescence biosensing methods for pharmaceuticals / 药物分析学报

Electrogenerated chemiluminescence (electrochemiluminescence, ECL) generates species at electrode surfaces, which undergoes electron-transfer reactions and forms excited states to emit light. It has be-come a very powerful analytical technique and has been widely used in such as clinical testing, bio-warfare agent detection, and pharmaceutical analysis. This review focuses on the current trends of molecular recognition-based biosensing methods for pharmaceutical analysis since 2010. It introduces a background of ECL and presents the recent ECL developments in ECL immunoassay (ECLIA), im-munosensors, enzyme-based biosensors, aptamer-based biosensors, and molecularly imprinted poly-mers (MIP)-based sensors. At last, the future perspective for these analytical methods is briefly discussed.

Establecimiento de condiciones más eficientes para la producción de biosensores de glucosa / Establishment of more efficient conditions for the production of glucose biosensors

Los biosensores son dispositivos móviles que permiten detectar de forma rápida y sencilla enfermedades del metabolismo e infecciones víricas de interés veterinario y clínico, como el rotavirus y la hepatitis B y C. Este trabajo tuvo como objetivo determinar las variables significativas del proceso de producción de los biosensores de glucosa fabricados en el Centro de Inmunoensayo (La Habana, Cuba). Se produjeron ocho corridas experimentales teniendo en cuenta los procedimientos normativos de operación implementados en la planta de producción de biosensores y se realizaron las evaluaciones de calidad correspondientes (pruebas de exactitud) para liberar analíticamente los lotes producidos. Los experimentos realizados proporcionaron información acerca de cuáles variables deben controlarse con más cuidado durante la producción a fin de evitar altos niveles de productos no conformes o el comportamiento errático del proceso. Las variables seleccionadas para el estudio fueron las relacionadas con la preparación de la solución enzimática. Con los resultados obtenidos se realizó un análisis de regresión múltiple para determinar los factores estadísticamente significativos del modelo, obteniéndose un coeficiente de determinación superior al 90 por ciento, logrando explicar el 98,637 por ciento de la variación entre los valores de porcentaje de exactitud y la media. Los factores que resultaron ser significativos fueron la concentración de la enzima glucosa oxidasa, la concentración del mediador eléctrico y la conductividad del agua ultrapura para un nivel de confianza del 95 por ciento. El análisis realizado arrojó resultados satisfactorios demostrando que variando parámetros del proceso productivo es posible disminuir los valores del porcentaje de exactitud(AU)

Biosensors are mobile devices that allow rapid and easy detection of metabolic diseases and viral infections of veterinary and clinical interest, such as rotavirus and hepatitis B and C. The objective of this work was to determine the significant variables of the production process of the glucose biosensors manufactured in the Immunoassay Center (Havana, Cuba). Eight experimental runs were carried out taking into account the normative operating procedures of the biosensor production plant. Accuracy tests were carried out to release produced batches. The experiments provided information about which factors should be carefully controlled during the manufacture procedure in order to avoid high levels of faulty products or the erratic behavior of the process. The factors selected for the study were those related with the preparation of the enzymatic solution. A multiple regression analysis was carried out to determine the statistically significant factors of the model. The coefficient of determination was higher than 90 percent, and the 98.637 percent of the variation between the values of percentage of accuracy and the mean value could be explained. The significant factors were the concentration of the glucose oxidase enzyme, the electric mediator concentration, and the ultrapure water conductivity (95 percent confidence level). The analysis carried out showed satisfactory results. In the present study, it was demonstrated that varying parameters of the production process it is possible to decrease the accuracy percentage values(AU)

A Highly Sensitive Electrochemical Biosensor for Detection of Adenosine Triphosphate Based on Space Block / 分析化学

In this work,a highly sensitive electrochemical biosensor for the detection of trace adenosine triphosphate (ATP) was proposed.The biosensor was based on porous anodic alumina (PAA) and SiO2 nanoparticles combining with several oligonucleotides to construct sandwich structure.It was characterized by scanning electron microscopy,fluorescence microscopy,differential pulse voltammetry and electrochemical impedance spectroscopy,which conformed to the reliability of the biosensor fabrication and the feasibility of the detection.In the presence of ATP,the sandwich structures could be destroyed.The variation of the current was directly corresponding to the amount of the ATP.The application of SiO2nanoparticles could effectively reduce the background and increase the sensitivity of the biosensor.The calibration curve of ATP was obtained in the range of 0.025-0.900 nmol/L with the detection limit of 13 pmol/L (S/N=3).Also,the biosensor exhibited a good specificity.Besides,the sensor was constructed easily and possessed excellent regeneration ability.The proposed biosensor was applied in detection of real sample such as mice blood.Therefore,the proposed ATP-sensing biosensor could be expected to be applied in clinical,pharmaceutical and environmental detection.

Enzymes immobilized in Langmuir-Blodgett films: Why determining the surface properties in Langmuir monolayer is important?

ABSTRACT In this review we discuss about the immobilization of enzymes in Langmuir-Blodgett films in order to determine the catalytic properties of these biomacromolecules when adsorbed on solid supports. Usually, the conformation of enzymes depends on the environmental conditions imposed to them, including the chemical composition of the matrix, and the morphology and thickness of the film. In this review, we show an outline of manuscripts that report the immobilization of enzymes as LB films since the 1980's, and also some examples of how the surface properties of the floating monolayer prepared previously to the transfer to the solid support are important to determine the efficiency of the resulting device.

Engineering of Thiamin Pyrophosphate Fluorescent Biosensors Based on Ribozyme Switches in Mammalian Cells / 分析化学

Thiamin pyrophosphate (TPP) is a thiamine (vitamin B1) derivative and an essential cofactor in oxidative metabolism of the sugars,fatty acids and amino acids in living cells.By now,numerous TPP-dependent artificial riboswitch systems have been developed to regulate target gene expression but limited in bacteria,fungi or plant cells.Herein,the activating (switch-on) and inhibiting (switch-off) TPP-depended hammerhead ribozyme switches,which are from previous reported structures of prokaryotes screening,were investigated in mammalian cells.These ribozyme switches were inserted into the 3'UTR of the enhanced green fluorescence protein (EGFP) gene to construct the efficient ribozyme-based artificial switches through overlap extension PCR cloning.The HEK293 cells were transfected with the engineered ribozyme switches at increasing concentration of TPP.The EGFP gene-regulatory ability was analyzed with fluorescent microscope and flow cytometry.These TPP-inducible gene regulation devices showed the obvious ligand dose-dependency and excellent specificity.Two switch-on and one switch-off constructs demonstrated 3.1-fold or 1.9-fold increment and 2.3-fold reduction of EGFP level respectively with 150 μ mol/L TPP.The ligand-responsive ribozyme switches,by tuning the change of TPP concentration into the visual reporter genetic expression in cells,enable an efficient development of label-free,noninvasive and high-specific biosensors in living mammalian cells.

Simultaneous Electrochemical Detection of Uric Acid and Dopamine Based on Graphene Quantum Dot Modified Glassy Carbon Electrode / 现代检验医学杂志

Objective To preparegraphene quantum dots (GQDs) and construct a novel biosensor for determination of dopamine (DA) and uric acid (UA).Methods The GQDs was prepared by carbonization method from citric acid as carbon sources.Differential pulse voltammetry was used by the modified electrodes to detect uric acid and dopamine,and the detection performance was evaluate.Collected three experimenters morning urine on July 29,2016.The proposed sensor was used for biological samples detection.Results The size of GQDs were between 3 to 5 nm,which was observed by transmission electron microscopy (TEM).The proposed sensor had good linear correlation of 50～600 μmol/L UA (r2 =0.996 6) and 2～ 240 μmol/L DA (r2 =0.992 5).In uric acid in urine samples' detection (n=3),RSD value was less than 3％.The standard addition recovery rates of UA and DA were in 95.7％～101.4％ and 96％～102％ respectively.Conclusion The biosensor based on GQDs for determination DA and UA had been constructed successfully.

Progresses and Prospects of Microbial Fuel Cell in Analytical Applications / 分析化学

Microbial fuel cell ( MFC ) is a type of energy device in which exoelectrogens are harnessed for directly converting the chemical energy of organic matter into electric energy. In addition to researches on the development of high-performance MFC, we have witnessed a rapid progress in the analytical application of MFCs. The MFC-based biosensors are simple and easy to operate, and they can also be used to monitor target online without external power sources, thus attracting more and more attention. Here, we summarize and discuss the progress on using MFCs for measuring biological oxygen demand ( BOD ) , volatile fatty acids, pollutant and toxic compounds, microbial activities and other substances. Furthermore, the design principle of MFC-based biosensors is clarified. The outlook and future prospect of MFC-based biosensors are also discussed in the end.

Application of aptamer-based upconverting phosphor biosensing technology in rapid detection for food safety / 国际生物医学工程杂志

The rapid detection technology in food safety plays a vital role in the field of preventive medicine.The traditional physical and chemical detection methods have some limitations,such as costly,difficult to operate and high requirements on environment,can not meet the needs of quality and safety on-site rapid screening,and are gradually replaced by emerging sensor detection technologies.The aptamer-upconversion biosensor technology is a novel rapid detection technology,which is based on the combination of functionalized upconversion nanomaterials and aptamer technology.Compared with the traditional immunofluorescence technology,it has advantages in sensitivity,specificity and stability,and is widely used in rapid detection.In this paper,the upconversion luminescence and aptamer technologies were briefly introduced,and the aptamer-based upconverting phosphor biosensing technology and its application in rapid detection of food safety were summarized.Based on the current research status,the bottleneck and the future development trend of this technology were analyzed,which provides a reference for the application of this technology in food safety and other fields.