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1.
Sci Rep ; 12(1): 19416, 2022 Nov 12.
Article in English | MEDLINE | ID: covidwho-2119170

ABSTRACT

The current COVID-19 pandemic outbreak poses a serious threat to public health, demonstrating the critical need for the development of effective and reproducible detection tests. Since the RT-qPCR primers are highly specific and can only be designed based on the known sequence, mutation sensitivity is its limitation. Moreover, the mutations in the severe acute respiratory syndrome ß-coronavirus (SARS-CoV-2) genome led to new highly transmissible variants such as Delta and Omicron variants. In the case of mutation, RT-qPCR primers cannot recognize and attach to the target sequence. This research presents an accurate dual-platform DNA biosensor based on the colorimetric assay of gold nanoparticles and the surface-enhanced Raman scattering (SERS) technique. It simultaneously targets four different regions of the viral genome for detection of SARS-CoV-2 and its new variants prior to any sequencing. Hence, in the case of mutation in one of the target sequences, the other three probes could detect the SARS-CoV-2 genome. The method is based on visible biosensor color shift and a locally enhanced electromagnetic field and significantly amplified SERS signal due to the proximity of Sulfo-Cyanine 3 (Cy3) and AuNPs intensity peak at 1468 cm-1. The dual-platform DNA/GO/AuNP biosensor exhibits high sensitivity toward the viral genome with a LOD of 0.16 ng/µL. This is a safe point-of-care, naked-eye, equipment-free, and rapid (10 min) detection biosensor for diagnosing COVID-19 cases at home using a nasopharyngeal sample.


Subject(s)
Biosensing Techniques , COVID-19 , Metal Nanoparticles , Humans , SARS-CoV-2/genetics , Gold , Pandemics , COVID-19/diagnosis , Biosensing Techniques/methods , Genome, Viral/genetics , DNA , RNA, Viral/genetics
2.
Anal Chem ; 94(47): 16436-16442, 2022 Nov 29.
Article in English | MEDLINE | ID: covidwho-2116713

ABSTRACT

Label-free electrochemiluminescence (ECL) immunoassays (lf-ECLIA), based on biomarker-induced ECL signal changes, have attracted increasing attention due to the simple, rapid, and low-cost detection of biomarkers without secondary antibodies and complicated labeling procedures. However, the interaction rule and mechanism between analytical interfaces and biomarkers have rarely been explored. Herein, the interactions between biomarkers and analytical interfaces constructed by assembly of a nanoluminophore and antibody-functionalized gold nanoparticles on an indium tin oxide electrode were studied. The nanoluminophore was synthesized by mixing Cu2+/l-cysteine chelate and N-(4-Aminobutyl)-N-ethylisoluminol-bifunctionalized gold nanoparticles with chitosan. It was found that positively charged biomarkers increased the ECL intensity, whereas negatively charged biomarkers decreased the ECL intensity. The assembly pH influenced the biomarker charges, which determined the ECL enhancement or inhibition. The detection pH only affected the ECL intensity but not the ECL changing trends. Based on the ECL signal changes, a charge-dependent lf-ECLIA was established, which exhibited inhibition responses to negatively charged human immunoglobulin G and copeptin and enhancement responses to positively charged cardiac troponin I, heart-type fatty acid binding protein, brain natriuretic peptide, and SARS-CoV-2 N protein. The linear range was 0.1-1000 pg/mL, and the detection limits were distributed in 0.024-0.091 pg/mL. Besides, a mechanism of the charge-dependent ECL enhancement and inhibition effects is proposed, which is very important for the development of new lf-ECLIA methodologies.


Subject(s)
Biosensing Techniques , COVID-19 , Metal Nanoparticles , Humans , Gold , Luminescent Measurements/methods , Biosensing Techniques/methods , SARS-CoV-2 , Immunoassay/methods , Biomarkers , Electrochemical Techniques/methods , Limit of Detection
3.
Biosensors (Basel) ; 12(11)2022 Nov 08.
Article in English | MEDLINE | ID: covidwho-2109936

ABSTRACT

Quick label-free virus screening and highly sensitive analytical tools/techniques are becoming extremely important in a pandemic. In this study, we developed a biosensing device based on the silicon nanoribbon multichannel and dielectrophoretic controlled sensors functionalized with SARS-CoV-2 spike antibodies for the use as a platform for the detection and studding of properties of viruses and their protein components. Replicatively defective viral particles based on vesicular stomatitis viruses and HIV-1 were used as carrier molecules to deliver the target SARS-CoV-2 spike S-proteins to sensory elements. It was shown that fully CMOS-compatible nanoribbon sensors have the subattomolar sensitivity and dynamic range of 4 orders. Specific interaction between S-proteins and antibodies leads to the accumulation of the negative charge on the sensor surface. Nonspecific interactions of the viral particles lead to the positive charge accumulation. It was shown that dielectrophoretic controlled sensors allow to estimate the effective charge of the single virus at the sensor surface and separate it from the charge associated with the binding of target proteins with the sensor surface.


Subject(s)
Biosensing Techniques , COVID-19 , Nanotubes, Carbon , Humans , SARS-CoV-2 , Biosensing Techniques/methods , Pandemics , Antibodies, Viral
4.
Sci Rep ; 12(1): 18155, 2022 Oct 28.
Article in English | MEDLINE | ID: covidwho-2096794

ABSTRACT

Coronavirus 2019 (COVID-19) spreads an extremely infectious disease where there is no specific treatment. COVID-19 virus had a rapid and unexpected spread rate which resulted in critical difficulties for public health and unprecedented daily life disruption. Thus, accurate, rapid, and early diagnosis of COVID-19 virus is critical to maintain public health safety. A graphite oxide-based field-effect transistor (GO-FET) was fabricated and functionalized with COVID-19 antibody for the purpose of real-time detection of COVID-19 spike protein antigen. Thermal evaporation process was used to deposit the gold electrodes on the surface of the sensor substrate. Graphite oxide channel was placed between the gold electrodes. Bimetallic nanoparticles of platinum and palladium were generated via an ultra-high vacuum (UHV) compatible system by sputtering and inert-gas condensation technique. The biosensor graphite oxide channel was immobilized with specific antibodies against the COVID-19 spike protein to achieve selectivity and specificity. This technique uses the attractive semiconductor characteristics of the graphite oxide-based materials resulting in highly specific and sensitive detection of COVID-19 spike protein. The GO-FET biosensor was decorated with bimetallic nanoparticles of platinum and palladium to investigate the improvement in the sensor sensitivity. The in-house developed biosensor limit of detection (LOD) is 1 fg/mL of COVID-19 spike antigen in phosphate-buffered saline (PBS). Moreover, magnetic labelled SARS-CoV-2 spike antibody were studied to investigate any enhancement in the sensor performance. The results indicate the successful fabrication of a promising field effect transistor biosensor for COVID-19 diagnosis.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Nanoparticles , Humans , Oxides , Platinum , Transistors, Electronic , Palladium , COVID-19 Testing , COVID-19/diagnosis , Spike Glycoprotein, Coronavirus , SARS-CoV-2 , Biosensing Techniques/methods , Gold
5.
Int J Mol Sci ; 23(21)2022 Oct 28.
Article in English | MEDLINE | ID: covidwho-2090210

ABSTRACT

The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a threat to public health and a worldwide crisis. This raised the need for quick, effective, and sensitive detection tools to prevent the rapid transmission rate of the infection. Therefore, this study aimed to develop an electrochemical impedance spectroscopy (EIS)-based aptasensor employing an interdigitated gold electrode (IDE) to detect SARS-CoV-2 Spike (S) glycoprotein and viral particles. This allowed us to sensitively detect SARS-CoV-2 S glycoprotein with a limit of detection (LOD) of 0.4 pg/mL in a buffer solution and to obtain a linear increase for concentrations between 0.2 to 0.8 pg/mL with high specificity. The proposed aptasensor also showed a good sensitivity towards the heat-inactivated SARS-CoV-2 variants in a buffer solution, where the Delta, Wuhan, and Alpha variants were captured at a viral titer of 6.45 ± 0.16 × 103 TCID50/mL, 6.20 × 104 TCID50/mL, and 5.32 ± 0.13 × 102 TCID50/mL, respectively. Furthermore, the detection of SARS-CoV-2 performed in a spiked human nasal fluid provided an LOD of 6.45 ± 0.16 × 103 TCID50/mL for the Delta variant in a 50 µL sample and a detection time of less than 25 min. Atomic force microscopy images complemented the EIS results in this study, revealing that the surface roughness of the IDE after each modification step increased, which indicates that the target was successfully captured. This label-free EIS-based aptasensor has promising potential for the rapid detection of SARS-CoV-2 in complex clinical samples.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , SARS-CoV-2/genetics , Dielectric Spectroscopy , Biosensing Techniques/methods , COVID-19/diagnosis , Limit of Detection , Gold/chemistry , Electrodes , Electrochemical Techniques/methods
6.
Biosensors (Basel) ; 12(11)2022 Oct 29.
Article in English | MEDLINE | ID: covidwho-2090001

ABSTRACT

Biolayer interferometry (BLI) is a well-established laboratory technique for studying biomolecular interactions important for applications such as drug development. Currently, there are interesting opportunities for expanding the use of BLI in other fields, including the development of rapid diagnostic tools. To date, there are no detailed frameworks for implementing BLI in target-recognition studies that are pivotal for developing point-of-need biosensors. Here, we attempt to bridge these domains by providing a framework that connects output(s) of molecular interaction studies with key performance indicators used in the development of point-of-need biosensors. First, we briefly review the governing theory for protein-ligand interactions, and we then summarize the approach for real-time kinetic quantification using various techniques. The 2020 PRISMA guideline was used for all governing theory reviews and meta-analyses. Using the information from the meta-analysis, we introduce an experimental framework for connecting outcomes from BLI experiments (KD, kon, koff) with electrochemical (capacitive) biosensor design. As a first step in the development of a larger framework, we specifically focus on mapping BLI outcomes to five biosensor key performance indicators (sensitivity, selectivity, response time, hysteresis, operating range). The applicability of our framework was demonstrated in a study of case based on published literature related to SARS-CoV-2 spike protein to show the development of a capacitive biosensor based on truncated angiotensin-converting enzyme 2 (ACE2) as the receptor. The case study focuses on non-specific binding and selectivity as research goals. The proposed framework proved to be an important first step toward modeling/simulation efforts that map molecular interactions to sensor design.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , Dielectric Spectroscopy , SARS-CoV-2 , COVID-19/diagnosis , Interferometry/methods , Biosensing Techniques/methods
7.
Biosensors (Basel) ; 12(10)2022 Oct 20.
Article in English | MEDLINE | ID: covidwho-2081840

ABSTRACT

The COVID-19 pandemic has severely impacted normal human life worldwide. Due to its rapid community spread and high mortality statistics, the development of prompt diagnostic tests for a massive number of samples is essential. Currently used traditional methods are often expensive, time-consuming, laboratory-based, and unable to handle a large number of specimens in resource-limited settings. Because of its high contagiousness, efficient identification of SARS-CoV-2 carriers is crucial. As the advantages of adopting biosensors for efficient diagnosis of COVID-19 increase, this narrative review summarizes the recent advances and the respective reasons to consider applying biosensors. Biosensors are the most sensitive, specific, rapid, user-friendly tools having the potential to deliver point-of-care diagnostics beyond traditional standards. This review provides a brief introduction to conventional methods used for COVID-19 diagnosis and summarizes their advantages and disadvantages. It also discusses the pathogenesis of COVID-19, potential diagnostic biomarkers, and rapid diagnosis using biosensor technology. The current advancements in biosensing technologies, from academic research to commercial achievements, have been emphasized in recent publications. We covered a wide range of topics, including biomarker detection, viral genomes, viral proteins, immune responses to infection, and other potential proinflammatory biomolecules. Major challenges and prospects for future application in point-of-care settings are also highlighted.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , COVID-19/diagnosis , Pandemics , SARS-CoV-2 , COVID-19 Testing , Biosensing Techniques/methods , Technology
8.
Anal Chem ; 94(43): 15155-15161, 2022 Nov 01.
Article in English | MEDLINE | ID: covidwho-2076960

ABSTRACT

Large-scale, rapid, and inexpensive serological diagnoses of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) are of great interest in reducing virus transmission at the population level; however, their development is greatly plagued by the lack of available point-of-care methods, leading to low detection efficiency. Herein, an ultrasensitive smartphone-based electrochemical immunoassay is reported for rapid (less than 5 min), low-cost, easy-to-implement detection of the SARS-CoV-2 nucleocapsid protein (SARS-CoV-2 N protein). Specifically, the electrochemical immunoassay was fabricated on a screen-printed carbon electrode coated with electrodeposited gold nanoparticles, followed by incubation of anti-N antibody (Ab) and bovine serum albumin as the working electrode. Accompanied by the antigen-antibody reaction between the SARS-CoV-2 N protein and the Ab, the electron transfer between the electroactive species [Fe(CN)6]3-/4- and the electrode surface is disturbed, resulting in reduced square-wave voltammetry currents at 0.075 V versus the Ag/AgCl reference electrode. The proposed immunoassay provided a good linear range with SARS-CoV-2 N protein concentrations within the scope of 0.01-1000 ng/mL (R2 = 0.9992) and the limit of detection down to 2.6 pg/mL. Moreover, the detection data are wirelessly transmitted to the interface of the smartphone, and the corresponding SARS-CoV-2 N protein concentration value is calculated and displayed. Therefore, the proposed portable detection mode offers great potential for self-differential diagnosis of residents, which will greatly facilitate the effective control and large-scale screening of virus transmission in resource-limited areas.


Subject(s)
Biosensing Techniques , COVID-19 , Metal Nanoparticles , Humans , SARS-CoV-2 , Gold , Point-of-Care Systems , Smartphone , COVID-19/diagnosis , Immunoassay/methods , Biosensing Techniques/methods
9.
Anal Chem ; 94(42): 14755-14760, 2022 10 25.
Article in English | MEDLINE | ID: covidwho-2076959

ABSTRACT

Development of convenient, accurate, and sensitive methods for rapid screening of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection is highly desired. In this study, we have developed a facile electrochemical aptasensor for the detection of the SARS-CoV-2 S1 protein amplified by dumbbell hybridization chain reaction (DHCR). A triangular prism DNA (TPDNA) nanostructure is first assembled and modified at the electrode interface. Due to the multiple thiol anchors, the immobilization is quite stable. The TPDNA nanostructure also provides an excellent scaffold for better molecular recognition efficiency on the top single-strand region (DHP0). The aptamer sequence toward the SARS-CoV-2 S1 protein is previously localized by partial hybridization with DHP0. In the presence of the target protein, the aptamer sequence is displaced and DHP0 is exposed. After further introduction of the fuel stands of DHCR, compressed DNA linear assembly occurs, and the product can be stacked on the TPDNA nanostructure for the enrichment of electrochemical species. This electrochemical method successfully detects the target protein in clinical samples, which provides a simple, robust, and accurate platform with great potential utility.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , COVID-19 , Nanostructures , Humans , SARS-CoV-2/genetics , Aptamers, Nucleotide/chemistry , COVID-19/diagnosis , DNA/chemistry , Nanostructures/chemistry , Electrochemical Techniques , Sulfhydryl Compounds , Biosensing Techniques/methods
10.
Biosensors (Basel) ; 12(10)2022 Oct 17.
Article in English | MEDLINE | ID: covidwho-2071229

ABSTRACT

The development of immunosensors to detect antibodies or antigens has stood out in the face of traditional methods for diagnosing emerging diseases such as the one caused by the SARS-CoV-2 virus. The present study reports the construction of a simplified electrochemical immunosensor using a graphene-binding peptide applied as a recognition site to detect SARS-CoV-2 antibodies. A screen-printed electrode was used for sensor preparation by adding a solution of peptide and reduced graphene oxide (rGO). The peptide-rGO suspension was characterized by scanning electron microscopy (SEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). The electrochemical characterization (electrochemical impedance spectroscopy-EIS, cyclic voltammetry-CV and differential pulse voltammetry-DPV) was performed on the modified electrode. The immunosensor response is based on the decrease in the faradaic signal of an electrochemical probe resulting from immunocomplex formation. Using the best set of experimental conditions, the analytic curve obtained showed a good linear regression (r2 = 0.913) and a limit of detection (LOD) of 0.77 µg mL-1 for antibody detection. The CV and EIS results proved the efficiency of device assembly. The high selectivity of the platform, which can be attributed to the peptide, was demonstrated by the decrease in the current percentage for samples with antibody against the SARS-CoV-2 S protein and the increase in the other antibodies tested. Additionally, the DPV measurements showed a clearly distinguishable response in assays against human serum samples, with sera with a response above 95% being considered negative, whereas responses below this value were considered positive. The diagnostic platform developed with specific peptides is promising and has the potential for application in the diagnosis of other infections that lead to high antibody titers.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Humans , Graphite/chemistry , Biosensing Techniques/methods , Electrochemical Techniques/methods , SARS-CoV-2 , Spectroscopy, Fourier Transform Infrared , Immunoassay , COVID-19/diagnosis , Electrodes , Limit of Detection , Peptides
11.
Biosensors (Basel) ; 12(10)2022 Oct 17.
Article in English | MEDLINE | ID: covidwho-2071228

ABSTRACT

A beautiful topic in its essence and content is represented by the powerful assistance of sensing methods and techniques for automatically revealing biological agents and biological functions in this era [...].


Subject(s)
Biosensing Techniques , COVID-19 , Humans , SARS-CoV-2 , COVID-19/diagnosis , Biosensing Techniques/methods , Biological Factors
12.
Biosensors (Basel) ; 12(10)2022 Oct 12.
Article in English | MEDLINE | ID: covidwho-2071227

ABSTRACT

The outbreak of Corona Virus Disease 2019 (COVID-19) has again emphasized the significance of developing rapid and highly sensitive testing tools for quickly identifying infected patients. Although the current reverse transcription polymerase chain reaction (RT-PCR) diagnostic techniques can satisfy the required sensitivity and specificity, the inherent disadvantages with time-consuming, sophisticated equipment and professional operators limit its application scopes. Compared with traditional detection techniques, optical biosensors based on nanomaterials/nanostructures have received much interest in the detection of SARS-CoV-2 due to the high sensitivity, high accuracy, and fast response. In this review, the research progress on optical biosensors in SARS-CoV-2 diagnosis, including fluorescence biosensors, colorimetric biosensors, Surface Enhancement Raman Scattering (SERS) biosensors, and Surface Plasmon Resonance (SPR) biosensors, was comprehensively summarized. Further, promising strategies to improve optical biosensors are also explained. Optical biosensors can not only realize the rapid detection of SARS-CoV-2 but also be applied to judge the infectiousness of the virus and guide the choice of SARS-CoV-2 vaccines, showing enormous potential to become point-of-care detection tools for the timely control of the pandemic.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , SARS-CoV-2 , COVID-19 Testing , COVID-19/diagnosis , COVID-19 Vaccines , Biosensing Techniques/methods
13.
Anal Chim Acta ; 1234: 340522, 2022 Nov 22.
Article in English | MEDLINE | ID: covidwho-2068604

ABSTRACT

At the end of 2019, the novel coronavirus disease 2019 (COVID-19), a cluster of atypical pneumonia caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been known as a highly contagious disease. Herein, we report the MXene/P-BiOCl/Ru(bpy)32+ heterojunction composite to construct an electrochemiluminescence (ECL) immunosensor for SARS-CoV-2 nucleocapsid protein (CoVNP) determination. Two-dimensional (2D) material ultrathin phosphorus-doped bismuth oxychloride (P-BiOCl) is exploited and first applied in ECL. 2D architectures MXene not only act as "soft substrate" to improve the properties of P-BiOCl, but also synergistically work with P-BiOCl. Owing to the inimitable set of bulk and interfacial properties, intrinsic high electrochemical conductivity, hydrophilicity and good biocompatible of 2D/2D MXene/P-BiOCl/Ru(bpy)32+, this as-exploited heterojunction composite is an efficient signal amplifier and co-reaction accelerator in the presence of tri-n-propylamine (TPA) as a coreactant. The proposed MXene/P-BiOCl/Ru(bpy)32+-TPA system exhibits a high and stable ECL signal and achieves ECL emission quenching for "signal on-off" recognition of CoVNP. Fascinatingly, the constructed ECL biosensor towards CoVNP allows a wide linear concentration range from 1 fg/mL to 10 ng/mL and a low limit of detection (LOD) of 0.49 fg/mL (S/N = 3). Furthermore, this presented strategy sheds light on designing a highly efficient ECL nanostructure through the combination of 2D MXene architectures with 2D semiconductor materials in the field of nanomedicine. This ECL biosensor can successfully detect CoVNP in human serum, which can promote the prosperity and development of diagnostic methods of SARS-CoV-2.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , Biosensing Techniques/methods , Bismuth , COVID-19/diagnosis , Electrochemical Techniques/methods , Immunoassay/methods , Luminescent Measurements/methods , Nucleocapsid Proteins , SARS-CoV-2
14.
Biosensors (Basel) ; 12(10)2022 Sep 29.
Article in English | MEDLINE | ID: covidwho-2065702

ABSTRACT

The spread and resurgence of the SARS-CoV-2 virus (COVID-19 disease) threatens human health and social relations. Prevention of COVID-19 disease partly relies on fabricating low-cost, point-of-care (POC) sensing technology that can rapidly and selectively detect the SARS-CoV-2 virus. We report a colorimetric, paper-based polydiacetylene (PDA) biosensor, designed to detect SARS-CoV-2 spike protein in artificial saliva. Analytical characterizations of the PDA sensor using NMR and FT-IR spectroscopy showed the correct structural elucidation of PCDA-NHS conjugation. The PDA sensor platform containing the N-Hydroxysuccinimide ester of 10, 12-pentacosadiynoic acid (PCDA-NHS) was divided into three experimental PCDA-NHS concentration groups of 10%, 20%, and 30% to optimize the performance of the sensor. The optimal PCDA-NHS molar concentration was determined to be 10%. The PDA sensor works by a color change from blue to red as its colorimetric output when the immobilized antibody binds to the SARS-CoV-2 spike protein in saliva samples. Our results showed that the PDA sensing platform was able to rapidly and qualitatively detect the SARS-CoV-2 spike protein within the concentration range of 1 to 100 ng/mL after four hours of incubation. Further investigation of pH and temperature showed minimal influence on the PDA sensor for the detection of COVID-19 disease. After exposure to the SARS-CoV-2 spike protein, smartphone images of the PDA sensor were used to assess the sensor output by using the red chromatic shift (RCS) of the signal response. These results indicate the potential and practical use of this PDA sensor design for the rapid, colorimetric detection of COVID-19 disease in developing countries with limited access to medical testing.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , SARS-CoV-2 , COVID-19/diagnosis , Colorimetry/methods , Saliva, Artificial , Spectroscopy, Fourier Transform Infrared , Biosensing Techniques/methods , Esters , Saliva
15.
Opt Express ; 30(12): 22233-22246, 2022 Jun 06.
Article in English | MEDLINE | ID: covidwho-2065093

ABSTRACT

We propose a measurement method for sensitive and label-free detections of virus-like particles (VLPs) using color images of nanoplasmonic sensing chips. The nanoplasmonic chip consists of 5×5 gold nanoslit arrays and the gold surface is modified with specific antibodies for spike protein. The resonant wavelength of the 430-nm-period gold nanoslit arrays underwater environment is about 570 nm which falls between the green and red bands of the color CCD. The captured VLPs by the specific antibodies shift the plasmonic resonance of the gold nanoslits. It results in an increased brightness of green pixels and decreased brightness of red pixels. The image contrast signals of (green - red) / (red + green) show good linearity with the surface particle density. The experimental tests show the image contrast method can detect 100-nm polystyrene particles with a surface density smaller than 2 particles/µm2. We demonstrate the application for direct detection of SARS-CoV-2 VLPs using a simple scanner platform. A detection limit smaller than 1 pg/mL with a detection time less than 30 minutes can be achieved.


Subject(s)
Biosensing Techniques , COVID-19 , Nanostructures , Antibodies , Biosensing Techniques/methods , Gold/chemistry , Humans , Nanostructures/chemistry , Polystyrenes , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Surface Plasmon Resonance/methods
16.
J Mater Chem B ; 10(41): 8478-8489, 2022 Oct 26.
Article in English | MEDLINE | ID: covidwho-2050572

ABSTRACT

The outbreak of the highly contagious disease COVID-19, which is triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), demands a rapid, low-cost, and highly sensitive immunosensor that can detect and identify the virus efficiently. Here, an electrochemical immunosensor based on a nanocomposite consisting of molybdenum disulfide nanosheets decorated with polydopamine (MoS2-PDA) is developed for highly sensitive detection of SARS-CoV-2 nucleocapsid protein (N protein). The MoS2-PDA nanocomposite possesses various hydroxyl and amine groups that have excellent chemistry with crosslinkers and act as adhesive agents to bind with the working electrode surface. Furthermore, the optical, functional, structural, vibrational, and morphological properties of the MoS2-PDA nanocomposite are studied using various characterization techniques such as UV-vis, FTIR, and Raman spectroscopies, XRD, and TEM. The electrochemical immunosensor is fabricated by functionalizing the MoS2-PDA nanocomposite with anti-SARS-CoV-2 nucleocapsid IgG antibody (Ab) and has a very high sensitivity against the N protein with a linear range between 10 ag mL-1 and 100 ng mL-1. The electrochemical immunosensor exhibits a lowest limit of detection (LOD) of 2.80 ag mL-1 and a limit of quantification (LOQ) of 8.48 ag mL-1via electrochemical impedance spectroscopy (EIS). Furthermore, the electrochemical immunosensor is successfully employed to detect the N protein in nasopharyngeal swab specimens and displays good consistency with the conventional RT-PCR test results. The results show that the MoS2-PDA nanocomposite-based electrochemical platform can serve as a highly sensitive and selective detector of N protein and will pave the way for the development of a point-of-care (POC) electrochemical immunosensor for rapid detection of other infectious viruses.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , Molybdenum/chemistry , Biosensing Techniques/methods , Electrochemical Techniques/methods , Immunoassay , SARS-CoV-2 , COVID-19/diagnosis , Immunoglobulin G , Amines
17.
Biosensors (Basel) ; 12(9)2022 Sep 19.
Article in English | MEDLINE | ID: covidwho-2043579

ABSTRACT

The recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has posed a great challenge for the development of ultra-fast methods for virus identification based on sensor principles. We created a structure modeling surface and size of the SARS-CoV-2 virus and used it in comparison with the standard antigen SARS-CoV-2-the receptor-binding domain (RBD) of the S-protein of the envelope of the SARS-CoV-2 virus from the Wuhan strain-for the development of detection of coronaviruses using a DNA-modified, surface-enhanced Raman scattering (SERS)-based aptasensor in sandwich mode: a primary aptamer attached to the plasmonic surface-RBD-covered Ag nanoparticle-the Cy3-labeled secondary aptamer. Fabricated novel hybrid plasmonic structures based on "Ag mirror-SiO2-nanostructured Ag" demonstrate sensitivity for the detection of investigated analytes due to the combination of localized surface plasmons in nanostructured silver surface and the gap surface plasmons in a thin dielectric layer of SiO2 between silver layers. A specific SERS signal has been obtained from SERS-active compounds with RBD-specific DNA aptamers that selectively bind to the S protein of synthetic virion (dissociation constants of DNA-aptamer complexes with protein in the range of 10 nM). The purpose of the study is to systematically analyze the combination of components in an aptamer-based sandwich system. A developed virus size simulating silver particles adsorbed on an aptamer-coated sensor provided a signal different from free RBD. The data obtained are consistent with the theory of signal amplification depending on the distance of the active compound from the amplifying surface and the nature of such a compound. The ability to detect the target virus due to specific interaction with such DNA is quantitatively controlled by the degree of the quenching SERS signal from the labeled compound. Developed indicator sandwich-type systems demonstrate high stability. Such a platform does not require special permissions to work with viruses. Therefore, our approach creates the promising basis for fostering the practical application of ultra-fast, amplification-free methods for detecting coronaviruses based on SARS-CoV-2.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , COVID-19 , Metal Nanoparticles , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , COVID-19/diagnosis , DNA/chemistry , Humans , Metal Nanoparticles/chemistry , SARS-CoV-2 , Silicon Dioxide , Silver/chemistry , Spectrum Analysis, Raman/methods
18.
Biosensors (Basel) ; 12(8)2022 Jul 29.
Article in English | MEDLINE | ID: covidwho-2043578

ABSTRACT

Many emerging technologies have the potential to improve health care by providing more personalized approaches or early diagnostic methods. In this review, we cover smartphone-based multiplexed sensors as affordable and portable sensing platforms for point-of-care devices. Multiplexing has been gaining attention recently for clinical diagnosis considering certain diseases require analysis of complex biological networks instead of single-marker analysis. Smartphones offer tremendous possibilities for on-site detection analysis due to their portability, high accessibility, fast sample processing, and robust imaging capabilities. Straightforward digital analysis and convenient user interfaces support networked health care systems and individualized health monitoring. Detailed biomarker profiling provides fast and accurate analysis for disease diagnosis for limited sample volume collection. Here, multiplexed smartphone-based assays with optical and electrochemical components are covered. Possible wireless or wired communication actuators and portable and wearable sensing integration for various sensing applications are discussed. The crucial features and the weaknesses of these devices are critically evaluated.


Subject(s)
Biosensing Techniques , Smartphone , Biomarkers/analysis , Biosensing Techniques/methods , Delivery of Health Care , Point-of-Care Systems
19.
Anal Biochem ; 658: 114928, 2022 Dec 01.
Article in English | MEDLINE | ID: covidwho-2041444

ABSTRACT

In the present work, an aptasensing method based on integration of RNA on Cu-MOF was developed for detection of C-Reactive Protein (CRP). Cu-MOF showed stimulated fluorescence and mimetic peroxidase enzymatic activity at the time and can be used as dual-signal transduction. CRP binding RNA was used as a highly selective recognition element and immobilized on the Cu-MOF. The immobilized RNA can block the peroxidase activity and fluorescence of the signal traducer probe. Adding CRP to the RNA/Cu-MOF will release RNA from the surface of Cu-MOF and recover both the stimulated fluorescence and peroxidase activity. A biosensor was built for detection of CRP using the two modes of transduction, either colorimetry or fluorometry. A dynamic linear range was obtained from 0.1 to 50 ng mL -1with a limit of detection (LOD) as small as 40 pg mL -1was calculated in fluorescence mode and 240 pg mL -1 as LOD in colorimetry mode. The LODs are lower than the LOD of nephelometric techniques used in clinical practice and is comparable to the normal clinical cutoff value in high-sensitivity CRP assays (1 µg/mL). The aptasensor was successfully applied for detection of CRP in Covid-19 patients with spike recoveries between 84 and 102% and RSD from 0.94% to 2.05%.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , COVID-19 , Humans , C-Reactive Protein , Immobilized Nucleic Acids , Biosensing Techniques/methods , Limit of Detection , Peroxidase , RNA
20.
Int J Mol Sci ; 23(18)2022 Sep 16.
Article in English | MEDLINE | ID: covidwho-2039872

ABSTRACT

Graphene and its derivatives show great potential for biosensing due to their extraordinary optical, electrical and physical properties. In particular, graphene and its derivatives have excellent optical properties such as broadband and tunable absorption, fluorescence bursts, and strong polarization-related effects. Optical biosensors based on graphene and its derivatives make nondestructive detection of biomolecules possible. The focus of this paper is to review the preparation of graphene and its derivatives, as well as recent advances in optical biosensors based on graphene and its derivatives. The working principle of face plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), fluorescence resonance energy transfer (FRET) and colorimetric sensors are summarized, and the advantages and disadvantages of graphene and its derivatives applicable to various types of sensors are analyzed, and the methods of surface functionalization of graphene and its derivatives are introduced; these optical biosensors can be used for the detection of a range of biomolecules such as single cells, cellular secretions, proteins, nucleic acids, and antigen-antibodies; these new high-performance optical sensors are capable of detecting changes in surface structure and biomolecular interactions with the advantages of ultra-fast detection, high sensitivity, label-free, specific recognition, and the ability to respond in real-time. Problems in the current stage of application are discussed, as well as future prospects for graphene and its biosensors. Achieving the applicability, reusability and low cost of novel optical biosensors for a variety of complex environments and achieving scale-up production, which still faces serious challenges.


Subject(s)
Biosensing Techniques , Graphite , Nucleic Acids , Biosensing Techniques/methods , Colorimetry , Graphite/chemistry , Spectrum Analysis, Raman , Surface Plasmon Resonance
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