Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 105
Filter
1.
Molecules ; 27(10)2022 May 21.
Article in English | MEDLINE | ID: covidwho-1875717

ABSTRACT

A novel molecularly imprinted polymer (MIP) has been developed based on a simple and sustainable strategy for the selective determination of citalopram (CTL) using screen-printed carbon electrodes (SPCEs). The MIP layer was prepared by electrochemical in situ polymerization of the 3-amino-4 hydroxybenzoic acid (AHBA) functional monomer and CTL as a template molecule. To simulate the polymerization mixture and predict the most suitable ratio between the template and functional monomer, computational studies, namely molecular dynamics (MD) simulations, were carried out. During the experimental preparation process, essential parameters controlling the performance of the MIP sensor, including CTL:AHBA concentration, number of polymerization cycles, and square wave voltammetry (SWV) frequency were investigated and optimized. The electrochemical characteristics of the prepared MIP sensor were evaluated by both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. Based on the optimal conditions, a linear electrochemical response of the sensor was obtained by SWV measurements from 0.1 to 1.25 µmol L-1 with a limit of detection (LOD) of 0.162 µmol L-1 (S/N = 3). Moreover, the MIP sensor revealed excellent CTL selectivity against very close analogues, as well as high imprinting factor of 22. Its applicability in spiked river water samples demonstrated its potential for adequate monitoring of CTL. This sensor offers a facile strategy to achieve portability while expressing a willingness to care for the environment.


Subject(s)
Molecular Imprinting , Molecularly Imprinted Polymers , Citalopram , Computer Simulation , Electrochemical Techniques/methods , Molecular Imprinting/methods
2.
Talanta ; 248: 123605, 2022 Oct 01.
Article in English | MEDLINE | ID: covidwho-1867807

ABSTRACT

In this work, a brief electrochemical aptasensor was developed for highly sensitive detection of SARS-CoV-2 antigen utilizing an aptamer-binding induced multiple hairpin assembly strategy for signal amplification. In the presence of SARS-CoV-2, a pair of aptamers was brought in a close proximity according to the aptamer-protein antigen binding, which initiated strand displacement reaction thereby triggering a multiple hairpin assembly to obtain long linear DNA concatemers on the electrode surface. As the fabricated hairpin probes were labeled with biotin, massive streptavidin-alkaline phosphatases (ST-ALP) could be further introduced on the electrode interface via biotin-streptavidin interaction thus generating strong electrochemical signal in electrolyte solution containing 1-naphthol phosphate. Benefiting from the non-enzymatic multiple hairpin assembly signal amplification strategy, the designed aptasensor for SARS-CoV-2 spike protein detection exhibited the wide linear range from 50 fg·mL-1 to 50 ng·mL-1 and low detection limit of 9.79 fg·mL-1. Meaningfully, this proposed electrochemical assay provided a potential application for the point of care analysis of viral diseases under ambient temperature.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , COVID-19 , Aptamers, Nucleotide/genetics , Biotin , COVID-19/diagnosis , Electrochemical Techniques , Gold , Humans , Limit of Detection , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Streptavidin
3.
Sci Rep ; 12(1): 8814, 2022 May 25.
Article in English | MEDLINE | ID: covidwho-1864765

ABSTRACT

The importance of monitoring environmental samples has gained a lot of prominence since the onset of COVID-19 pandemic, and several surveillance efforts are underway using gold standard, albeit expensive qPCR-based techniques. Electrochemical DNA biosensors could offer a potential cost-effective solution suitable for monitoring of environmental water samples in lower middle income countries. In this work, we demonstrate electrochemical detection of amplicons as long as [Formula: see text] obtained from Phi6 bacteriophage (a popular surrogate for SARS-CoV-2) isolated from spiked lake water samples, using ENIG finish PCB electrodes with no surface modification. The electrochemical sensor response is thoroughly characterised for two DNA fragments of different lengths ([Formula: see text] and [Formula: see text]), and the impact of salt in PCR master mix on methylene blue (MB)-DNA interactions is studied. Our findings establish that length of the DNA fragment significantly determines electrochemical sensitivity, and the ability to detect long amplicons without gel purification of PCR products demonstrated in this work bodes well for realisation of fully-automated solutions for in situ measurement of viral load in water samples.


Subject(s)
Biosensing Techniques , COVID-19 , Nucleic Acids , DNA/genetics , Electrochemical Techniques , Electrodes , Humans , Pandemics , SARS-CoV-2/genetics , Water
4.
Anal Chem ; 94(20): 7149-7157, 2022 05 24.
Article in English | MEDLINE | ID: covidwho-1829920

ABSTRACT

Virus detection at the point-of-care facility has become an alarming topic in the research community. The latest coronavirus pandemic has highlighted the limitations of current conventional virus detection methods. Compared to nonelectrochemical sensors, electrochemical sensors provide the ideal platform for rapid, cheap, fast, sensitive, and selective diagnosis of several viruses, particularly at point-of-care facilities. This article highlights the most promising studies reported over the past decade to detect a broad spectrum of viruses using voltammetry, amperometry, and electrochemical impedance spectroscopy.


Subject(s)
Biosensing Techniques , Coronavirus Infections , Viruses , Biosensing Techniques/methods , Coronavirus Infections/diagnosis , Electrochemical Techniques , Humans , Pandemics , Point-of-Care Systems
5.
Bioelectrochemistry ; 146: 108106, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1828002

ABSTRACT

The development of advanced electrode materials and the combination of aptamer with them have improved dramatically the performance of aptasensors. Herein, a new architecture based on copper hydroxide nanorods (Cu(OH)2 NRs) are directly grown on the surface of screen printed carbon electrode (SPCE) using a two-step in situ, very simple and fast strategy and was used as a high-performance substrate for immobilization of aptamer strings, as well as an electrochemical probe to development a label-free electrochemical aptasensor for SARS-CoV-2 spike glycoprotein measurement. The Cu(OH)2 NRs was characterized using X-ray Diffraction (XRD) and electron microscopy (FESEM). In the presence of SARS-CoV-2 spike glycoprotein, a decrease in Cu(OH)2 NRs-associated peak current was observed that can be owing to the target-aptamer complexes formation and thus blocking the electron transfer of Cu(OH)2 NRs on the surface of electrode. This strategy exhibited wide dynamic range in of 0.1 fg mL-1 to 1.2 µg mL-1 and with a high sensitivity of 1974.43 µA mM-1 cm-2 and low detection limit of 0.03 ± 0.01 fg mL-1 of SARS-CoV-2 spike glycoprotein deprived of any cross-reactivity in the presence of possible interference species. In addition, the good reproducibility, repeatability, high stability and excellent feasibility in real samples of saliva and viral transport medium (VTM) were found from the provided aptasensor. Also, the aptasensor efficiency was evaluated by real samples of sick and healthy individuals and compared with the standard polymerase chain reaction (PCR) method and acceptable results were observed.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , COVID-19 , Nanotubes , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Electrochemical Techniques/methods , Electrodes , Humans , Reproducibility of Results , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
6.
Anal Chim Acta ; 1211: 339904, 2022 Jun 08.
Article in English | MEDLINE | ID: covidwho-1819418

ABSTRACT

Until now, COVID-19 caused by SARS-CoV-2 is engulfing the worldwide and still ranging to date, continuing to threaten the public health. The main challenge facing COVID-19 epidemic is short of fast-response and high-efficiency methods to determine SARS-CoV-2 viral pathogens. Herein, a nanobody-based label-free photoelectrochemical (PEC) immunosensor has been fabricated for rapidly detecting SARS-CoV-2 spike protein. As a small-size and high-stability antibody, nanobody was directly and well immobilized with Au nanoparticles and TiO2 spheres by the interaction. Au deposited TiO2 nanomaterial possessed 8.5 times photoelectric performance in comparison with TiO2 in the presence of electron donor owing to surface plasma resonance effect of Au. Based on the steric hindrance effect, this immunoassay platform realized the linear detection from 0.015 to 15000 pg mL-1, and a limit of detection was low as 5 fg mL-1. The label-free PEC immunoassay design provides a new idea for convenient, rapid, and efficient test of SARS-CoV-2 spike protein and broadens further application of nanobody as an identification agent to specific biomarkers.


Subject(s)
Biosensing Techniques , COVID-19 , Metal Nanoparticles , Biosensing Techniques/methods , COVID-19/diagnosis , Electrochemical Techniques/methods , Gold , Humans , Immunoassay/methods , Limit of Detection , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
7.
Anal Chim Acta ; 1205: 339739, 2022 May 01.
Article in English | MEDLINE | ID: covidwho-1813993

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is considered one of the worst pandemic outbreaks worldwide. This ongoing pandemic urgently requires rapid, accurate, and specific testing devices to detect the virus. We report a simple electrochemical biosensor based on a highly specific synthetic peptide to detect SARS-CoV-2 Spike protein. Unlike other reported electrochemical biosensors involving nanomaterials or complex approaches, our electrochemical platform uses screen-printed gold electrodes functionalized with the thiolated peptide, whose interaction with the Spike protein is directly followed by Electrochemical Impedance Spectroscopy. The electrochemical platform was Spike protein concentration-dependent, with high sensitivity and reproducibility and a limit of detection of 18.2 ng/mL when tested in Spike protein commercial solutions and 0.01 copies/mL in lysed SARS-CoV-2 particles. The label-free biosensor successfully detected the Spike protein in samples from infected patients straightforwardly in only 15 min. The simplicity of the proposed format combined with an on-demand designed peptide opens the path for detecting other pathogen-related antigens.


Subject(s)
Biosensing Techniques , COVID-19 , Biosensing Techniques/methods , COVID-19/diagnosis , Electrochemical Techniques/methods , Humans , Peptides , Reproducibility of Results , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
8.
Biosensors (Basel) ; 12(4)2022 Apr 16.
Article in English | MEDLINE | ID: covidwho-1809706

ABSTRACT

Thrombin plays a central role in hemostasis and its imbalances in coagulation can lead to various pathologies. It is of clinical significance to develop a fast and accurate method for the quantitative detection of thrombin. Electrochemical aptasensors have the capability of combining the specific selectivity from aptamers with the extraordinary sensitivity from electrochemical techniques and thus have attracted considerable attention for the trace-level detection of thrombin. Nanomaterials and nanostructures can further enhance the performance of thrombin aptasensors to achieve high sensitivity, selectivity, and antifouling functions. In highlighting these material merits and their impacts on sensor performance, this paper reviews the most recent advances in label-free electrochemical aptasensors for thrombin detection, with an emphasis on nanomaterials and nanostructures utilized in sensor design and fabrication. The performance, advantages, and limitations of those aptasensors are summarized and compared according to their material structures and compositions.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Nanostructures , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Electrochemical Techniques , Nanostructures/chemistry , Thrombin
9.
ACS Appl Mater Interfaces ; 14(17): 19204-19211, 2022 May 04.
Article in English | MEDLINE | ID: covidwho-1805548

ABSTRACT

Efficient and timely testing has taken center stage in the management, control, and monitoring of the current COVID-19 pandemic. Simple, rapid, cost-effective diagnostics are needed that can complement current polymerase chain reaction-based methods and lateral flow immunoassays. Here, we report the development of an electrochemical sensing platform based on single-walled carbon nanotube screen-printed electrodes (SWCNT-SPEs) functionalized with a redox-tagged DNA aptamer that specifically binds to the receptor binding domain of the SARS-CoV-2 spike protein S1 subunit. Single-step, reagentless detection of the S1 protein is achieved through a binding-induced, concentration-dependent folding of the DNA aptamer that reduces the efficiency of the electron transfer process between the redox tag and the electrode surface and causes a suppression of the resulting amperometric signal. This aptasensor is specific for the target S1 protein with a dissociation constant (KD) value of 43 ± 4 nM and a limit of detection of 7 nM. We demonstrate that the target S1 protein can be detected both in a buffer solution and in an artificial viral transport medium widely used for the collection of nasopharyngeal swabs, and that no cross-reactivity is observed in the presence of different, non-target viral proteins. We expect that this SWCNT-SPE-based format of electrochemical aptasensor will prove useful for the detection of other protein targets for which nucleic acid aptamer ligands are made available.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , COVID-19 , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , COVID-19/diagnosis , Electrochemical Techniques/methods , Electrodes , Humans , Limit of Detection , Pandemics , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
10.
Anal Chim Acta ; 1208: 339846, 2022 May 22.
Article in English | MEDLINE | ID: covidwho-1797342

ABSTRACT

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the outbreak of the 2019 coronavirus (COVID-19) disease, which greatly challenges the global economy and health. Simple and sensitive diagnosis of COVID-19 at the early stage is important to prevent the spread of pandemics. Herein, we have proposed a target-triggered cascade signal amplification in this work for sensitive analysis of SARS-CoV-2 RNA. Specifically, the presence of SARS-CoV-2 RNA can trigger the catalytic hairpin assembly to generate plenty of DNA duplexes with free 3'-OH termini, which can be recognized and catalyzed by the terminal deoxynucleotidyl transferase (TdT) to generate long strand DNA. The prolonged DNA can absorb substantial Ru(NH3)63+ molecules via electrostatic interaction and produce an enhanced current response. The incorporation of catalytic hairpin assembly and TdT-mediated polymerization effectively lowers the detection limit to 45 fM, with a wide linear range from 0.1 pM to 3000 pM. Moreover, the proposed strategy possesses excellent selectivity to distinguish target RNA with single-base mismatched, three-base mismatched, and random sequences. Notably, the proposed electrochemical biosensor can be applied to analyze targets in complex circumstances containing 10% saliva, which implies its high stability and anti-interference. Moreover, the proposed strategy has been successfully applied to SARS CoV-2 RNA detection in clinical samples and may have the potential to be cultivated as an effective tool for COVID-19 diagnosis.


Subject(s)
Biosensing Techniques , COVID-19 , COVID-19/diagnosis , COVID-19 Testing , DNA/chemistry , DNA Nucleotidylexotransferase/metabolism , Electrochemical Techniques , Humans , Limit of Detection , Nucleic Acid Amplification Techniques , RNA, Viral/genetics , SARS-CoV-2
11.
Talanta ; 245: 123482, 2022 Aug 01.
Article in English | MEDLINE | ID: covidwho-1796082

ABSTRACT

Infection caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is responsible for the Coronavirus disease (COVID-19) and the current pandemic. Its mortality rate increases, demonstrating the imperative need for acute and rapid diagnostic tools as an alternative to current serological tests and molecular techniques. Features of electrochemical genosensor devices make them amenable for fast and accurate testing closer to the patient. This work reports on a specific electrochemical genosensor for SARS-CoV-2 detection and discrimination against homologous respiratory viruses. The electrochemical biosensor was assembled by immobilizing thiolated capture probes on top of maleimide-coated magnetic particles, followed by specific target hybridization between the capture and biotinylated signaling probes in a sandwich-type manner. The probes were rigorously designed bioinformatically and tested in vitro. Enzymatic complexes based on streptavidin-horseradish peroxidase linked the biotinylated signaling probe to render the biosensor electrochemical response. The genosensor showed to reach a sensitivity of 174.4 µA fM-1 and a limit of detection of 807 fM when using streptavidin poly-HRP20 enzymatic complex, detected SARS-CoV-2 specifically and discriminated it against homologous viruses in spiked samples and samples from SARS-CoV-2 cell cultures, a step forward to detect SARS-CoV-2 closer to the patient as a promising way for diagnosis and surveillance of COVID-19.


Subject(s)
Biosensing Techniques , COVID-19 , Biosensing Techniques/methods , COVID-19/diagnosis , Electrochemical Techniques/methods , Humans , Pandemics , SARS-CoV-2/genetics , Streptavidin
12.
Biosensors (Basel) ; 12(4)2022 Apr 14.
Article in English | MEDLINE | ID: covidwho-1792820

ABSTRACT

Chronic inflammatory diseases, such as cancer, diabetes mellitus, stroke, ischemic heart diseases, neurodegenerative conditions, and COVID-19 have had a high number of deaths worldwide in recent years. The accurate detection of the biomarkers for chronic inflammatory diseases can significantly improve diagnosis, as well as therapy and clinical care in patients. Graphene derivative materials (GDMs), such as pristine graphene (G), graphene oxide (GO), and reduced graphene oxide (rGO), have shown tremendous benefits for biosensing and in the development of novel biosensor devices. GDMs exhibit excellent chemical, electrical and mechanical properties, good biocompatibility, and the facility of surface modification for biomolecular recognition, opening new opportunities for simple, accurate, and sensitive detection of biomarkers. This review shows the recent advances, properties, and potentialities of GDMs for developing robust biosensors. We show the main electrochemical and optical-sensing methods based on GDMs, as well as their design and manufacture in order to integrate them into robust, wearable, remote, and smart biosensors devices. We also describe the current application of such methods and technologies for the biosensing of chronic disease biomarkers. We also describe the current application of such methods and technologies for the biosensing of chronic disease biomarkers with improved sensitivity, reaching limits of detection from the nano to atto range concentration.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Biomarkers , Biosensing Techniques/methods , COVID-19/diagnosis , Chronic Disease , Electrochemical Techniques/methods , Graphite/chemistry , Humans
13.
Biosens Bioelectron ; 208: 114198, 2022 Jul 15.
Article in English | MEDLINE | ID: covidwho-1748197

ABSTRACT

The COVID-19 pandemic has highlighted the need for rapid, low-cost, and sensitive virus detection platforms to monitor and mitigate widespread outbreaks. Electrochemical sensors are a viable choice to fill this role but still require improvements to the signal magnitude, especially for early detection and low viral loads. Herein, finite element analysis of a novel biosensor concept for single virion counting using a generator-collector microelectrode design is presented. The proposed design combines a redox-cycling amplified electrochemical current with electrophoresis-driven electrode-particle collision for rapid virus detection. The effects of experimental (e.g. scan rate, collector bias) and geometric factors are studied to optimize the sensor design. Two generator-collector configurations are explored: a ring-disk configuration to analyze sessile droplets and an interdigitated electrode (IDE) design housed in a microchannel. For the ring-disk configuration, we calculate an amplification factor of ∼5 and collector efficiency of ∼0.8 for a generator-collector spacing of 600 nm. For the IDE, the collector efficiency is even larger, approaching unity. The dual-electrode mode is critical for increasing the current and electric field strength. As a result, the current steps upon virus capture are more than an order of magnitude larger compared to single-mode. Additionally, single virus capture times are reduced from over 700 s down to ∼20 s. Overall, the frequency of virus capture and magnitude of the electrochemical current steps depend on the virus properties and electrode configuration, with the IDE capable of single virus detection within seconds owing to better particle confinement in the microchannel.


Subject(s)
Biosensing Techniques , COVID-19 , COVID-19/diagnosis , Electrochemical Techniques , Electrophoresis , Humans , Microelectrodes , Oxidation-Reduction , Pandemics , Virion
14.
Biosensors (Basel) ; 12(3)2022 Feb 25.
Article in English | MEDLINE | ID: covidwho-1725509

ABSTRACT

Worldwide, human health is affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hence, the fabrication of the biosensors to diagnose SARS-CoV-2 is critical. In this paper, we report an electrochemical impedance spectroscopy (EIS)-based aptasensor for the determination of the SARS-CoV-2 receptor-binding domain (SARS-CoV-2-RBD). For this purpose, the carbon nanofibers (CNFs) were first decorated with gold nanoparticles (AuNPs). Then, the surface of the carbon-based screen-printed electrode (CSPE) was modified with the CNF-AuNP nanocomposite (CSPE/CNF-AuNP). After that, the thiol-terminal aptamer probe was immobilized on the surface of the CSPE/CNF-AuNP. The surface coverage of the aptamer was calculated to be 52.8 pmol·cm-2. The CSPE/CNF-AuNP/Aptamer was then used for the measurement of SARS-CoV-2-RBD by using the EIS method. The obtained results indicate that the signal had a linear-logarithmic relationship in the range of 0.01-64 nM with a limit of detection of 7.0 pM. The proposed aptasensor had a good selectivity to SARS-CoV-2-RBD in the presence of human serum albumin; human immunoglobulins G, A, and M, hemagglutinin, and neuraminidase. The analytical performance of the aptasensor was studied in human saliva samples. The present study indicates a practical application of the CSPE/CNF-AuNP/Aptamer for the determination of SARS-CoV-2-RBD in human saliva samples with high sensitivity and accuracy.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , COVID-19 , Metal Nanoparticles , Nanocomposites , Nanofibers , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , COVID-19/diagnosis , Carbon/chemistry , Dielectric Spectroscopy , Electrochemical Techniques/methods , Electrodes , Gold/chemistry , Humans , Limit of Detection , Metal Nanoparticles/chemistry , Nanofibers/chemistry , SARS-CoV-2
15.
ACS Biomater Sci Eng ; 8(3): 964-1000, 2022 03 14.
Article in English | MEDLINE | ID: covidwho-1713110

ABSTRACT

Graphene- and carbon-based nanomaterials are key materials to develop advanced biosensors for the sensitive detection of many biomarkers owing to their unique properties. Biosensors have attracted increasing interest because they allow efficacious, sensitive, selective, rapid, and low-cost diagnosis. Biosensors are analytical devices based on receptors for the process of detection and transducers for response measuring. Biosensors can be based on electrochemical, piezoelectric, thermal, and optical transduction mechanisms. Early virus identification provides critical information about potentially effective and selective therapies, extends the therapeutic window, and thereby reduces morbidity. The sensitivity and selectivity of graphene can be amended via functionalizing it or conjoining it with further materials. Amendment of the optical and electrical features of the hybrid structure by introducing appropriate functional groups or counterparts is especially appealing for quick and easy-to-use virus detection. Various techniques for the electrochemical detection of viruses depending on antigen-antibody interactions or DNA hybridization are discussed in this work, and the reasons behind using graphene and related carbon nanomaterials for the fabrication are presented and discussed. We review the existing state-of-the-art directions of graphene-based classifications for detecting DNA, protein, and hormone biomarkers and summarize the use of the different biosensors to detect several diseases, like cancer, Alzheimer's disease, and diabetes, to sense numerous viruses, including SARS-CoV-2, human immunodeficiency virus, rotavirus, Zika virus, and hepatitis B virus, and to detect the recent pandemic virus COVID-19. The general concepts, mechanisms of action, benefits, and disadvantages of advanced virus biosensors are discussed to afford beneficial evidence of the creation and manufacture of innovative virus biosensors. We emphasize that graphene-based nanomaterials are ideal candidates for electrochemical biosensor engineering due to their special and tunable physicochemical properties.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Nanostructures , Zika Virus Infection , Zika Virus , Biosensing Techniques/methods , Carbon , Electrochemical Techniques/methods , Humans , Nanostructures/chemistry , SARS-CoV-2
16.
Anal Chem ; 94(10): 4446-4454, 2022 03 15.
Article in English | MEDLINE | ID: covidwho-1713092

ABSTRACT

The enrichment of co-reactants is one of the keys to improving the sensitivity of electrochemiluminescence (ECL) detection. This work developed a novel hydrophobic localized enrichment strategy of co-reactants utilizing the inner hydrophobic cavity of ß-cyclodextrin (ß-CD). Pt nanoparticles (Pt NPs) were grown in situ on the coordination sites for metal ions of ß-CD to prepare the ß-CD-Pt nanocomposite, which could not only enrich co-reactant 3-(dibutylamino) propylamine (TDBA) highly efficiently through its hydrophobic cavity but also immobilize TDBA via the Pt-N bond. Meanwhile, the carboxyl-functionalized poly[2,5-dioctyl-1,4-phenylene] (PDP) polymer nanoparticles (PNPs) were developed as excellent ECL luminophores. With SARS-CoV-2 nucleocapsid protein (ncovNP) as a model protein, the TDBA-ß-CD-Pt nanocomposite combined PDP PNPs to construct a biosensor for ncovNP determination. The PDP PNPs were modified onto the surface of a glassy carbon electrode (GCE) to capture the first antibody (Ab1) and further capture antigen and secondary antibody complexes (TDBA-ß-CD-Pt@Ab2). The resultant biosensor with a sandwich structure achieved a highly sensitive detection of ncovNP with a detection limit of 22 fg/mL. TDBA-ß-CD-Pt shared with an inspiration in hydrophobic localized enrichment of co-reactants for improving the sensitivity of ECL detection. The luminophore PDP PNPs integrated TDBA-ß-CD-Pt to provide a promising and sensitive ECL platform, offering a new method for ncovNP detection.


Subject(s)
Biosensing Techniques , COVID-19 , Metal Nanoparticles , Biosensing Techniques/methods , Electrochemical Techniques/methods , Humans , Limit of Detection , Luminescent Measurements/methods , Metal Nanoparticles/chemistry , Nucleocapsid Proteins , Polymers/chemistry , SARS-CoV-2
17.
Mikrochim Acta ; 189(3): 125, 2022 03 01.
Article in English | MEDLINE | ID: covidwho-1712245

ABSTRACT

A novel electrochemical sensor is reported for the detection of the antiviral drug favipiravir based on the core-shell nanocomposite of flower-like molybdenum disulfide (MoS2) nanospheres and molecularly imprinted polymers (MIPs). The MoS2@MIP core-shell nanocomposite was prepared via the electrodeposition of a MIP layer on the MoS2 modified electrode, using o-phenylenediamine as the monomer and favipiravir as the template. The selective binding of target favipiravir at the MoS2@MIP core-shell nanocomposite produced a redox signal in a concentration dependent manner, which was used for the quantitative analysis. The preparation process of the MoS2@MIP core-shell nanocomposite was optimized. Under the optimal conditions, the sensor exhibited a wide linear response range of 0.01 ~ 100 nM (1.57*10-6 ~ 1.57*10-2 µg mL-1) and a low detection limit of 0.002 nM (3.14*10-7 µg mL-1). Application of the sensor was demonstrated by detecting favipiravir in a minimum amount of 10 µL biological samples (urine and plasma). Satisfied results in the recovery tests indicated a high potential of favipiravir monitoring in infectious COVID-19 samples.


Subject(s)
Amides/analysis , Antiviral Agents/analysis , Disulfides/chemistry , Molecularly Imprinted Polymers/chemistry , Molybdenum/chemistry , Nanocomposites/chemistry , Nanospheres/chemistry , Pyrazines/analysis , Amides/blood , Amides/therapeutic use , Amides/urine , Antiviral Agents/blood , Antiviral Agents/therapeutic use , Antiviral Agents/urine , COVID-19/drug therapy , COVID-19/virology , Electrochemical Techniques/methods , Humans , Limit of Detection , Oxidation-Reduction , Pyrazines/blood , Pyrazines/therapeutic use , Pyrazines/urine , Reproducibility of Results , SARS-CoV-2/isolation & purification
18.
J Mater Chem B ; 10(6): 870-879, 2022 02 09.
Article in English | MEDLINE | ID: covidwho-1704333

ABSTRACT

In this study, we developed a crystal-reconstructed-BiVO4 aptamer photoelectrochemical (PEC) biosensor by a high-energy laser treatment technique. This biosensor achieves a limit of detection (LOD) (0.82 ag mL-1), linear detection range (1 ag mL-1 to 2 ng mL-1), and resolution ratio (∼18 molecules per mL) for prostate-specific antigen (PSA) tumor biomarker detection. Furthermore, reconstructed surface microstructure and oxygen vacancy doping energy formation after crystal reconstruction induce the stereo-hindrance effect and photogenerated hole energy is reduced during PSA target detection. In this case, a photocurrent inhibition phenomenon for PSA detection is noticed. Based on this photocurrent inversion phenomenon, some dysoxidizable nucleonic acid tumor (miRNA-21) and virus biomarkers (RdRp-COVID) can be detected with a LOD level of ∼10-16 M by linking the corresponding base paring probe on the surface of the crystal-reconstructed photoanode. In addition to high sensitivity, this PEC biosensor presents high detection specificity, stability, and accuracy in clinical verification. Thus, this crystal-reconstructed PEC biosensor shows application potential in the fields of multi-tumor or viral biomarker detection.


Subject(s)
COVID-19 , Neoplasms , Biomarkers, Tumor , Electrochemical Techniques/methods , Humans , Male , Prostate-Specific Antigen , Semiconductors
19.
ACS Nano ; 16(3): 4726-4733, 2022 03 22.
Article in English | MEDLINE | ID: covidwho-1703529

ABSTRACT

Nucleic acids, including circulating tumor DNA (ctDNA), microRNA, and virus DNA/RNA, have been widely applied as potential disease biomarkers for early clinical diagnosis. In this study, we present a concept of DNA nanostructures transitions for the construction of DNA bipedal walking nanomachine, which integrates dual signal amplification for direct nucleic acid assay. DNA hairpins transition is developed to facilitate the generation of multiple target sequences; meanwhile, the subsequent DNA dumbbell-wheel transition is controlled to achieve the bipedal walker, which cleaves multiple tracks around electrode surface. Through combination of strand displacement reaction and digestion cycles, DNA monolayer at the electrode interface could be engineered and target-induced signal variation is realized. In addition, pH-assisted detachable intermolecular DNA triplex design is utilized for the regeneration of electrochemical biosensor. The high consistency between this work and standard quantitative polymerase chain reaction is validated. Moreover, the feasibilities of this biosensor to detect ctDNA and SARS-CoV-2 RNA in clinical samples are demonstrated with satisfactory accuracy and reliability. Therefore, the proposed approach has great potential applications for nucleic acid based clinical diagnostics.


Subject(s)
Biosensing Techniques , COVID-19 , COVID-19/diagnosis , DNA/chemistry , Electrochemical Techniques , Humans , Limit of Detection , Nucleic Acid Amplification Techniques , RNA, Viral/genetics , Reproducibility of Results , SARS-CoV-2/genetics
20.
ACS Appl Mater Interfaces ; 14(8): 10844-10855, 2022 Mar 02.
Article in English | MEDLINE | ID: covidwho-1692677

ABSTRACT

The widespread and long-lasting effect of the COVID-19 pandemic has called attention to the significance of technological advances in the rapid diagnosis of SARS-CoV-2 virus. This study reports the use of a highly stable buffer-based zinc oxide/reduced graphene oxide (bbZnO/rGO) nanocomposite coated on carbon screen-printed electrodes for electrochemical immuno-biosensing of SARS-CoV-2 nuelocapsid (N-) protein antigens in spiked and clinical samples. The incorporation of a salt-based (ionic) matrix for uniform dispersion of the nanomixture eliminates multistep nanomaterial synthesis on the surface of the electrode and enables a stable single-step sensor nanocoating. The immuno-biosensor provides a limit of detection of 21 fg/mL over a linear range of 1-10 000 pg/mL and exhibits a sensitivity of 32.07 ohms·mL/pg·mm2 for detection of N-protein in spiked samples. The N-protein biosensor is successful in discriminating positive and negative clinical samples within 15 min, demonstrating its proof of concept used as a COVID-19 rapid antigen test.


Subject(s)
Antigens, Viral/analysis , COVID-19/diagnosis , Coronavirus Nucleocapsid Proteins/analysis , Graphite/chemistry , Nanocomposites/chemistry , Zinc Oxide/chemistry , Antibodies, Immobilized/immunology , Antigens, Viral/immunology , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Coronavirus Nucleocapsid Proteins/immunology , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Electrodes , Humans , Immunoassay/instrumentation , Immunoassay/methods , Limit of Detection , Phosphoproteins/analysis , Phosphoproteins/immunology , Proof of Concept Study , SARS-CoV-2/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL