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1.
Bioelectrochemistry ; 158: 108722, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38697015

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis is the need of the hour, as cases are persistently increasing, and new variants are constantly emerging. The ever-changing nature of the virus leading to multiple variants, has brought an imminent need for early, accurate and rapid detection methods. Herein, we have reported the design and fabrication of Screen-Printed Electrodes (SPEs) with graphene oxide (GO) as working electrode and modified with specific antibodies for SARS-CoV-2 Receptor Binding Domain (RBD). Flexibility of design, and portable nature has made SPEs the superior choice for electrochemical analysis. The developed immunosensor can detect RBD as low as 0.83 fM with long-term storage capacity. The fabricated SPEs immunosensor was tested using a miniaturized portable device and potentiostat on 100 patient nasopharyngeal samples and corroborated with RT-PCR data, displayed 94 % sensitivity. Additionally, the in-house developed polyclonal antibodies detected RBD antigen of the mutated Omicron variant of SARS-CoV-2 successfully. We have not observed any cross-reactivity/binding of the fabricated immunosensor with MERS (cross-reactive antigen) and Influenza A H1N1 (antigen sharing common symptoms). Hence, the developed SPEs sensor may be applied for bedside point-of-care diagnosis of SARS-CoV-2 using miniaturized portable device, in clinical samples.


Subject(s)
Biosensing Techniques , COVID-19 , Electrodes , Graphite , SARS-CoV-2 , Graphite/chemistry , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , SARS-CoV-2/genetics , Humans , COVID-19/diagnosis , COVID-19/virology , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Immunoassay/methods , Immunoassay/instrumentation , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/analysis , Limit of Detection
2.
Food Chem ; 439: 138120, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38064831

ABSTRACT

Lateral flow assays (LFAs) are among the utmost cost-efficient, paper-based point-of-care (POC) diagnostic devices. Herein, we have reported the fabrication of a competitive LFA for on-site detection of penicillin. Various parameters such as Ab concentration for conjugation, Pen-BSA conjugate concentration, pore size of membrane, and blocking buffer were standardised for the fabrication of LFA. Different concentrations of penicillin (1 pM-1 mM) were added to the sample pad to observe the color intensity. The visual detection limit (LOD) achieved from the LFA was 10 nM for Penicillin that correlated with the LOD calculated from the 'ColorGrab' colorimeter application. Additionally, LFA showed insignificant cross reactivity with other ß-lactam antibiotics and were also validated with spiked food samples such as milk, meat and egg. Hence, the fabricated LFA can be successfully utilised for the POC detection of penicillin in food samples on large scale.


Subject(s)
Gold , Metal Nanoparticles , Limit of Detection , Penicillins , Point-of-Care Systems
3.
Int J Biol Macromol ; 258(Pt 2): 128979, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38154710

ABSTRACT

Salmonella typhimurium (S. typhi) a predominant foodborne pathogen, significantly impacting global public health. Therefore, timely diagnosis is imperative to safeguard overall human health. To address this, we developed a novel CRISPR/Cas12a-mediated electrochemical detection system (biosensor) for targeting the SifA gene of S. typhi. To construct the biosensor, we utilized a screen-printed gold electrode (SPGE) as an electrochemical transducer and CRISPR/Cas12a for detection of SifA gene of S. typhi. The developed electrochemical biosensor exhibited an exceptional detection limit of 0.634 ± 0.029 pM, which was determined through differential pulse voltammetry (DPV) by utilizing a potentiostat. We compared the fabricated biosensor with gold standard RT-PCR and the visual detection limit of SifA was found to be 10 µM (in spiked buffer samples). The lower detection limit of fabricated biosensor provides an upper edge over the RT-PCR. Further, the fabricated biosensor also has the potential to serve as a rapid, stable, efficient, and early detection tool for S. typhi, offering promising advancements in diagnostic realms.


Subject(s)
Biosensing Techniques , CRISPR-Cas Systems , Humans , Salmonella typhimurium , Electrodes , Heart Rate
4.
Environ Res ; 238(Pt 1): 117127, 2023 12 01.
Article in English | MEDLINE | ID: mdl-37716396

ABSTRACT

Endosulfan (En) is an organochlorine biocide (OCB), that ends up in the environment due to the enzymatic and microsomal activity even though it is not accumulated in living tissue. Endosulfan acts as an organic micro-pollutant which disrupts land as well as aquatic ecosystem. In the present study, we chemically modified endosulfan and conjugated it with a carrier protein to produce an immune response. The generated antibodies were tested for specificity against En, and characterized before further use. Transition Metal Chalcogenides (TMC) showed excellent optoelectrical potential due to its direct bandgap and distinct physical as well as chemical characteristics. Herein, we synthesized a novel nanohybrid using MoSe2 in combination with graphene oxide (GO) and characterized thoroughly. This was similar to graphene-based metal chalcogenides which were further used in this study to fabricate biosensor for the sensitive detection of En. The in-house developed antibodies (En-Ab) were coupled with the nanohybrid to make MoSe2/GO/En-Ab electrode. Fabricated electrode was tested for electrochemical parameters using differential pulse voltammetry (DPV). Working efficiency of the fabricated electrode i.e., limit of detection (LOD), was found to be 7.45 ppt. In conclusion, we hypothesized that the synthesized TMC nanohybrids could be employed for biosensing of endosulfan, and can likely be developed to test field samples.


Subject(s)
Graphite , Graphite/chemistry , Endosulfan , Ecosystem , Electrochemical Techniques/methods , Limit of Detection
5.
Pathol Res Pract ; 248: 154720, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37542862

ABSTRACT

Neuroendocrine neoplasms (NENs) comprise malignancies involving neuroendocrine cells that often lead to fatal pathological conditions. Despite escalating global incidences, NENs still have poor prognoses. Interestingly, research indicates an intricate association of tumor viruses with NENs. However, there is a dearth of comprehension of the complete scenario of NEN pathophysiology and its precise connections with the tumor viruses. Interestingly, several cutting-edge experiments became helpful for further screening of NET for the presence of polyomavirus, Human papillomavirus (HPV), Kaposi sarcoma-associated herpesvirus (KSHV), Epstein Barr virus (EBV), etc. Current research on the neuroendocrine tumor (NET) pathogenesis provides new information concerning their molecular mechanisms and therapeutic interventions. Of note, scientists observed that metastatic neuroendocrine tumors still have a poor prognosis with a palliative situation. Different oncolytic vector has already demonstrated excellent efficacies in clinical studies. Therefore, oncolytic virotherapy or virus-based immunotherapy could be an emerging and novel therapeutic intervention. In-depth understanding of all such various aspects will aid in managing, developing early detection assays, and establishing targeted therapeutic interventions for NENs concerning tumor viruses. Hence, this review takes a novel approach to discuss the dual role of tumor viruses in association with NENs' pathophysiology as well as its potential therapeutic interventions.


Subject(s)
Carcinoma, Neuroendocrine , Epstein-Barr Virus Infections , Herpesvirus 8, Human , Neuroendocrine Tumors , Humans , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/therapy , Herpesvirus 4, Human , Neuroendocrine Tumors/therapy , Neuroendocrine Tumors/pathology
6.
Bioeng Transl Med ; 8(3): e10506, 2023 May.
Article in English | MEDLINE | ID: mdl-37206199

ABSTRACT

Japanese encephalitis (JE), a neglected tropical zoonotic disease prevalent in south-east Asian and western pacific countries, caused by the flavivirus JE virus (JEV), has a dearth of electrochemical point-of-care (PoC) diagnostic tools available to manage endemic breakouts. To overcome this, we have developed a screen-printed carbon electrode (SPCE) immunosensor for rapid PoC detection of JEV nonstructural 1 (NS1) antigen (Ag), found circulating in serum of infected individuals using a smartphone based portable "Sensit" device. The modification of SPCE surface with JEV NS1 antibody (Ab) was confirmed via observation of globular protein structures via scanning electron microscopy (SEM), increase in electrode surface hydrophilicity via contact angle measurement and decrease in current via differential pulse voltammetry (DPV). The fabrication and testing parameters were optimized based on highest current output obtained using DPV. The SPCE was tested for detection limit of target JEV NS1 Ag ranging from 1 fM to 1 µM, which was determined as 0.45 fM in spiked serum. The disposable immunosensor was also found to be highly specific in detecting JEV NS1 Ag over other flaviviral NS1 Ag. Finally, the modified SPCE was clinically validated by testing 62 clinical JEV samples using both a portable miniaturized electrochemical "Sensit" device coupled with a smartphone and a laboratory-based potentiostat. The results were corroborated with gold-standard RT-PCR and showed 96.77% accuracy, 96.15% sensitivity, and 97.22% specificity. Hence, this technique may further be developed into a one-step rapid diagnostic tool for JEV, especially in rural areas.

7.
Chemosphere ; 330: 138704, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37100248

ABSTRACT

With the aim of monocrotophos pesticides detection in environmental and food samples at point-of-care (PoC) application, this research, for the first time, explores silica alcogel as an immobilization matrix to support the development of in-house customized nano-enabled "chromagrid-lighbox" as a sensing system. This system is fabricated using laboratory waste materials and demonstrates the detection of highly hazardous monocrotophos pesticide using a smartphone. Nano-enabled chromagrid is a chip-like assembly filled with silica alcogel -a nanomaterial (hence the name "nano-enabled" chromagrid), and "chromogenic reagents" which is required for the enzymatic detection of monocrotophos. Lightbox is the imaging station fabricated to provide constant lighting conditions to the chromagrid to capture accurate colorimetric data. The silica alcogel used in this system was synthesized from Tetraethyl orthosilicate (TEOS) via a sol-gel method and characterized using advanced analytical techniques. Further, three chromagrid assays were developed for the optical detection of monocrotophos with a low detection limit (LOD) at 0.421 ng ml-1 (by α-NAc chromagrid assay), 0.493 ng ml-1 (by DTNB chromagrid assay) and 0.811 ng ml-1 (by IDA chromagrid assay). The developed novel PoC chromagrid-lightbox system is capable of on-site detection of monocrotophos in environmental as well as food samples. This system is able to be manufacture prudently using recyclable waste plastic. Overall, such developed eco-friendly PoC testing system will surely manage rapid detection of monocrotophos pesticide needed for environmental and sustainable agricultural management.


Subject(s)
Monocrotophos , Pesticides , Point-of-Care Systems , Smartphone , Silicon Dioxide
8.
Colloids Surf B Biointerfaces ; 226: 113319, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37120932

ABSTRACT

Salmonella strain is a prevalent pathogen, affecting poultry industry and hence human population around the world. Host-specific pathogen infections including fowl typhoid, pullorum disease and typhoid fever affects poultry birds, causing huge economic loss worldwide. This study explored the fabrication of immunochromatographic (ICG) strip by colorimetric method integrated with smartphone ColorGrab application for the detection of Salmonella using in-house generated antibodies (Abs) conjugated with gold nanoparticles. The developed point-of-care diagnostic platform was fabricated in-house and tested to detect the presence of Salmonella in a linear range of 107-100 CFU/mL with the limit of detection (LOD) of 103, 102 and 104 CFU/mL respectively, for Salmonella gallinarum (S.gal), Salmonella pullorum (S.pul) and Salmonella enteritidis (S.ent), which was further confirmed by smartphone-based ColorGrab application. The fabricated ICG strips were further validated using spiked fecal, meat, and milk samples which provided results in 10 mins with stability at 4 °C and 37 °C up to 28 days. Hence, the fabricated in-house ICG strip can be used as a portable, cost-effective diagnostic device for rapid detection of Salmonella strains in food samples.


Subject(s)
Metal Nanoparticles , Poultry Diseases , Salmonella Infections, Animal , Animals , Humans , Gold , Point-of-Care Systems , Smartphone , Salmonella Infections, Animal/diagnosis , Poultry Diseases/diagnosis , Salmonella , Immunoassay , Chickens
9.
Diagnostics (Basel) ; 13(5)2023 Feb 28.
Article in English | MEDLINE | ID: mdl-36900059

ABSTRACT

Personalized point-of-care testing (POCT) devices, such as wearable sensors, enable quick access to health monitoring without the use of complex instruments. Wearable sensors are gaining popularity owing to their ability to offer regular and continuous monitoring of physiological data by dynamic, non-invasive assessments of biomarkers in biofluids such as tear, sweat, interstitial fluid and saliva. Current advancements have concentrated on the development of optical and electrochemical wearable sensors as well as advances in non-invasive measurements of biomarkers such as metabolites, hormones and microbes. For enhanced wearability and ease of operation, microfluidic sampling, multiple sensing, and portable systems have been incorporated with materials that are flexible. Although wearable sensors show promise and improved dependability, they still require more knowledge about interaction between the target sample concentrations in blood and non-invasive biofluids. In this review, we have described the importance of wearable sensors for POCT, their design and types of these devices. Following which, we emphasize on the current breakthroughs in the application of wearable sensors in the realm of wearable integrated POCT devices. Lastly, we discuss the present obstacles and forthcoming potentials including the use of Internet of Things (IoT) for offering self-healthcare using wearable POCT.

10.
Chemosphere ; 321: 138148, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36804249

ABSTRACT

Endosulfan (ES) is an extensively utilized agricultural pesticide in developing countries, despite its life-threatening toxic effects. In this study, we propose a sensitive detection method against endosulfan using multiwalled carbon nanotubes (MWCNT). Herein, we have conjugated endosulfan with bovine serum albumin (BSA) via zero-length conjugation method and successfully confirmed with various biophysical techniques. Endosulfan antibodies (ES-Ab) were raised in-house, fabricated on electrodes coupled with MWCNT, and optimized to achieve maximum peak current by varying the parameters such as MWCNT and antibody concentration, scan rate, temperature, pH, and response time using voltammetry. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and impedance spectroscopies (IS) were performed for electrochemical analysis. The fabricated immunosensor was also evaluated for its cross reactivity with isodrin, chlorpyrifos, and monocrotophos. The limit of detection for ES was found to be 0.184 ppt in standard buffer (range 0.001 ppt-100 ppb). Additionally, spiked ES in water, animal feed, root, and leaf extract samples were also analyzed and validated by HPLC. To summarize, the fabricated electrode can be used for successful detection of endosulfan in the agricultural sector to elude the lethal effect at large.


Subject(s)
Biosensing Techniques , Nanotubes, Carbon , Animals , Endosulfan , Limit of Detection , Biosensing Techniques/methods , Immunoassay , Electrodes , Antibodies , Electrochemical Techniques/methods
11.
Diagnostics (Basel) ; 13(4)2023 Feb 12.
Article in English | MEDLINE | ID: mdl-36832187

ABSTRACT

Two-dimensional (2D) nanomaterials with chemical and structural diversity have piqued the interest of the scientific community due to their superior photonic, mechanical, electrical, magnetic, and catalytic capabilities that distinguish them from their bulk counterparts. Among these 2D materials, two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides with a general chemical formula of Mn+1XnTx (where n = 1-3), together known as MXenes, have gained tremendous popularity and demonstrated competitive performance in biosensing applications. In this review, we focus on the cutting-edge advances in MXene-related biomaterials, with a systematic summary on their design, synthesis, surface engineering approaches, unique properties, and biological properties. We particularly emphasize the property-activity-effect relationship of MXenes at the nano-bio interface. We also discuss the recent trends in the application of MXenes in accelerating the performance of conventional point of care (POC) devices towards more practical approaches as the next generation of POC tools. Finally, we explore in depth the existing problems, challenges, and potential for future improvement of MXene-based materials for POC testing, with the goal of facilitating their early realization of biological applications.

12.
Biotechnol Genet Eng Rev ; : 1-29, 2023 Jan 14.
Article in English | MEDLINE | ID: mdl-36641600

ABSTRACT

One of the greatest challenges faced during surgical procedures is closing and healing of wounds, which are essential in the field of orthopaedics, trauma, intensive care and general surgery. One of the main causes of death has been linked to chronic wounds, especially in immunosuppressant or diabetic patients. Due to increasing chronic wound fatality along with different pathologies associated with them, the current therapeutic methods are insufficient which has established an eminent need for innovative techniques. Traditionally, wound healing was carried out using formulations and ointments containing silver combined with different biomaterial, but was found to be toxic. Hence, the advent of alternative nanomaterial-based therapeutics for effective wound healing have come into existence. In this review, we have discussed an overview of wound infections such as different wound types, the wound healing process, dressing of wounds and conventional therapies. Furthermore, we have explored various nanotechnological advances made in wound healing therapy which include the use of promising candidates such as organic, inorganic, hybrid nanoparticles/nanocomposites and synthetic/natural polymer-based nanofibers. This review further highlights nanomaterial-based applications for regeneration of tissue in wound healing and can provide a base for researchers worldwide to contribute to this advancing medical area of wound therapy.

13.
J Med Virol ; 95(1): e28416, 2023 01.
Article in English | MEDLINE | ID: mdl-36541714

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic has emphasized the need for development of a rapid diagnostic device for the effective treatment and its mitigation. Lateral flow immunoassay (LFIA) belongs to a class of diagnostic devices, which has the benefit of providing quick results, easy to handle, low cost, and on-site applicable. So far, several LFIA has been developed for the detection of infectious severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), however, only a few of them are antigen (Ag)-based. Here, we describe an antibody (Ab)-labeled gold nanoparticles (AuNPs)-based LFIA (AuNPs-LFIA) for the detection of Receptor-Binding Domain (RBD) of SARS-CoV-2. For this, RBD Ab of SARS-CoV-2 was conjugated with the AuNPs, which served as a detecting probe. The fabricated LFIA strip was optimized for different parameters such as membrane pore size, blocking conditions, Ab coating concentration, and conjugate incubation. The optimized LFIA strips were validated in spiked buffer samples and the optimal limit of detection was found to be 1 ng/ml, which was confirmed by a smartphone-based application. Moreover, the developed AuNPs-LFIA strips effectively detected RBD Ag in 100 clinical samples with 94.3% sensitivity and 90.9% specificity in clinical samples when compared with the gold standard (RT-PCR). The fabricated LFIAs are reported to have storage stability of up to 21 days at 4°C and room temperature (RT). Hence, the developed LFIA can be used as a portable, cost-effective diagnostic device for rapid detection of SARS-CoV-2.


Subject(s)
COVID-19 , Metal Nanoparticles , Humans , SARS-CoV-2 , Gold , COVID-19/diagnosis , Smartphone , Metal Nanoparticles/chemistry , Immunoassay/methods
14.
Food Chem ; 398: 133846, 2023 Jan 01.
Article in English | MEDLINE | ID: mdl-35961172

ABSTRACT

The unregulated usage of Cephalexin (CFX) in animal source food products has led to antimicrobial resistance (AMR) in humans. Graphene quantum dots (GQD) are zero-dimensional nanomaterials possessing both unique optical and electrical propertiesbased on their tuneable size that serves as an excellent signal enhancer. The fluorescence quenching and conductive properties of GQD were exploited for the detection of CFX. In this study, a zero-length conjugation approach was utilized to develop Cephalexin-Bovine Serum Albumin (CFX-BSA) conjugate and used to develop antibodies (Ab). Conjugated CFX-BSA Abs with GQD enhanced the electrochemical response of the sensor for sensitive detection of CFX. The fabricated electrode was optimised by Electrochemical Impedance Spectroscopy (EIS). The limit of detection for CFX was found to be 0.53 fM in standard buffer with negligible cross-reactivity against other ß-lactam antibiotics. The biofunctionalized electrode based on GQD-antibody may potentially be miniaturised for on-site detection of other antibiotics in food samples.


Subject(s)
Biosensing Techniques , Graphite , Quantum Dots , Anti-Bacterial Agents , Antibodies , Biosensing Techniques/methods , Cephalexin , Electrochemical Techniques/methods , Graphite/chemistry , Humans , Immunoassay/methods , Limit of Detection , Quantum Dots/chemistry
15.
Biosens Bioelectron X ; 12: 100284, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36448023

ABSTRACT

The recent COVID-19 infection outbreak has raised the demand for rapid, highly sensitive POC biosensing technology for intelligent health and wellness. In this direction, efforts are being made to explore high-performance nano-systems for developing novel sensing technologies capable of functioning at point-of-care (POC) applications for quick diagnosis, data acquisition, and disease management. A combination of nanostructures [i.e., 0D (nanoparticles & quantum dots), 1D (nanorods, nanofibers, nanopillars, & nanowires), 2D (nanosheets, nanoplates, nanopores) & 3D nanomaterials (nanocomposites and complex hierarchical structures)], biosensing prototype, and micro-electronics makes biosensing suitable for early diagnosis, detection & prevention of life-threatening diseases. However, a knowledge gap associated with the potential of 0D, 1D, 2D, and 3D nanostructures for the design and development of efficient POC sensing is yet to be explored carefully and critically. With this focus, this review highlights the latest engineered 0D, 1D, 2D, and 3D nanomaterials for developing next-generation miniaturized, portable POC biosensors development to achieve high sensitivity with potential integration with the internet of medical things (IoMT, for miniaturization and data collection, security, and sharing), artificial intelligence (AI, for desired analytics), etc. for better diagnosis and disease management at the personalized level.

16.
Nanoscale Adv ; 4(18): 3966-3977, 2022 Sep 13.
Article in English | MEDLINE | ID: mdl-36133331

ABSTRACT

Lateral flow assays (LFAs) are one of the most economical, point-of-care (PoC) diagnostic assays that exploit the colorimetric properties of gold nanoparticles (AuNPs). Up to the best of our knowledge, no rapid antigen-based LFA exists for Japanese Encephalitis Virus (JEV) detection. Herein, we have reported a novel portable sandwich-type LFA for on-site detection of the non-structural 1 (NS1) secretory protein of JEV. In-house JEV NS1 antibodies (Abs) were generated and labelled with AuNPs as immunoprobes. A glass fibre membrane conjugate pad was soaked with AuNPs-Ab solution, while the JEV NS1 Ab and anti-rabbit IgG 2° Ab were coated as the test and control lines, respectively, on a nitrocellulose (NC) membrane. Different layers of the LFA were fabricated and various parameters were standardised for optimum colour intensity development. JEV negative serum samples spiked with JEV NS1 Ags (linear range - 1 pg ml-1 to 1 µg ml-1) were applied onto the sample pad and the intensity of the red colour developed on the test line increased with increasing concentration of Ag. The visual limit of detection (LOD) determined from the LFA was 10 pg ml-1, which corresponded to the LOD determined by the graphical data obtained from ImageJ software and the Colorimeter smartphone application. Furthermore, the colorimetric based immunosensor showed minimal non-specific detection of other closely related flaviviral NS1 Ags in the spiked serum, provided a rapid result within 10 min, showed storage stability up to a month at 4 °C, successfully detected the JEV NS1 protein in clinically infected pig serum samples, and hence, may be developed into a PoC screening diagnostic kit for JEV.

17.
Colloids Surf B Biointerfaces ; 219: 112812, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36088829

ABSTRACT

The impact of uncontrolled antibiotic use in animals has subsequently led to emergence of antibiotic-resistant bacteria among humans due to consumption of animal by-products. Hence, to investigate antibiotic contamination in animal origin food products, we have developed a reduced graphene oxide (rGO) based immunosensor using fabricated electrode conjugated with anti-Penicillin antibody (rGO/Pen-Ab) for sensitive detection of Penicillin G. To execute this, Penicillin was first conjugated with Bovine Serum Albumin (BSA) which was confirmed via chromatographic, spectroscopic and electrophoretic-based techniques against both the in-house developed Penicillin conjugate (Pen-BSA) as well as the commercial Penicillin conjugate (Com-Pen-BSA). Further, we fabricated electrode based on one step synthesized rGO and immobilized with antibodies generated against Pen-BSA (Pen-Ab), and Com-Pen-BSA (Com-Pen-Ab), separately for detection of Penicillin. Each synthesis and conjugation step was confirmed by different spectroscopic methods. For efficient working of the electrode, various parameters were optimized using Voltammetry. The limit of detection for Penicillin G against Pen-Ab and Com-Pen-Ab was determined as 0.724 pM and 0.668 pM respectively and both displayed negligible cross reactivity against other ß-lactam antibiotics (Cefalexin and Ampicillin). Furthermore, antibiotics were also detected in spiked milk, egg and meat samples and the electrode was evaluated for repeatability and storage stability. In conclusion, in-house developed Pen-Ab showed better sensitivity as compared to Com-Pen-Ab. The fabricated rGO/Pen-Ab biosensor shows future potential for rapid detection of penicillin and other ß-lactam antibiotics for safe consumption of animal by-products in humans.

19.
ACS Appl Bio Mater ; 5(7): 3563-3572, 2022 07 18.
Article in English | MEDLINE | ID: mdl-35775242

ABSTRACT

Coronavirus disease (COVID-19) is an infectious disease that has posed a global health challenge caused by the SARS-CoV-2 virus. Early management and diagnosis of SARS-CoV-2 are crucial for the timely treatment, traceability, and reduction of viral spread. We have developed a rapid method using a Graphene-based Field-Effect Transistor (Gr-FET) for the ultrasensitive detection of SARS-CoV-2 Spike S1 antigen (S1-Ag). The in-house developed antispike S1 antibody (S1-Ab) was covalently immobilized on the surface of a carboxy functionalized graphene channel using carbodiimide chemistry. Ultraviolet-visible spectroscopy, Fourier-Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), Optical Microscopy, Raman Spectroscopy, Scanning Electron Microscopy (SEM), Enzyme-Linked Immunosorbent Assays (ELISA), and device stability studies were conducted to characterize the bioconjugation and fabrication process of Gr-FET. In addition, the electrical response of the device was evaluated by monitoring the change in resistance caused by Ag-Ab interaction in real time. For S1-Ag, our Gr-FET devices were tested in the range of 1 fM to 1 µM with a limit of detection of 10 fM in the standard buffer. The fabricated devices are highly sensitive, specific, and capable of detecting low levels of S1-Ag.


Subject(s)
COVID-19 , Graphite , COVID-19/diagnosis , Graphite/chemistry , Humans , Neoplasm Proteins , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
20.
Biosensors (Basel) ; 12(6)2022 May 26.
Article in English | MEDLINE | ID: mdl-35735514

ABSTRACT

Salmonellosis is a major cause of foodborne infections, caused by Salmonella, posing a major health risk. It possesses the ability to infiltrate the food supply chain at any point throughout the manufacturing, distribution, processing or quality control process. Salmonella infection has increased severely and requires effective and efficient methods for early monitoring and detection. Traditional methods, such as real-time polymerase chain reaction and culture plate, consume a lot of time and are labor-intensive. Therefore, new quick detection methods for on-field applications are urgently needed. Biosensors provide consumer-friendly approaches for quick on-field diagnoses. In the last few years, there has been a surge in research into the creation of reliable and advanced electrochemical sensors for the detection of Salmonella strains in food samples. Electrochemical sensors provide extensive accuracy and reproducible results. Herein, we present a comprehensive overview of electrochemical sensors for the detection of Salmonella by focusing on various mechanisms of electrochemical transducer. Further, we explain new-generation biosensors (microfluidics, CRISPR- and IOT-based) for point-of care applications. This review also highlights the limitations of developing biosensors in Salmonella detection and future possibilities.


Subject(s)
Biosensing Techniques/trends , Electrochemical Techniques/trends , Salmonella Infections/diagnosis , Biosensing Techniques/methods , Electrochemical Techniques/methods , Humans , Real-Time Polymerase Chain Reaction , Salmonella/genetics , Salmonella/isolation & purification , Salmonella Food Poisoning/diagnosis , Salmonella Food Poisoning/microbiology , Salmonella Infections/microbiology , Time Factors
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