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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.
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
3.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
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
10.
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
11.
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
12.
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
13.
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
14.
Int J Mol Sci ; 23(3)2022 Jan 22.
Article in English | MEDLINE | ID: covidwho-1686809

ABSTRACT

Recently, the studies on developing sensors and biosensors-with an obvious interdisciplinary character-have drawn the attention of many researchers specializing in various fundamental, but also complex domains such as chemistry, biochemistry, physics, biophysics, biology, bio-pharma-medicine, and bioengineering. Along these lines, the present paper is structured into three parts, and is aimed at synthesizing the most relevant studies on the construction and functioning of versatile devices, of electrochemical sensors and biosensors, respectively. The first part presents examples of the most representative scientific research focusing on the role and the importance of the phenylalanine, tyrosine, and tryptophan amino acids, selected depending on their chemical structure and their impact on the central nervous system. The second part is dedicated to presenting and exemplifying conductor polymers and molecularly imprinted polymers used as sensitive materials in achieving electrochemical sensors and biosensors. The last part of the review analyzes the sensors and biosensors developed so far to detect amino acids with the aid of conductor polymers and molecularly imprinted polymers from the point of view of the performances obtained, with emphasis on the detection methods, on the electrochemical reactions that take place upon detection, and on the electroanalytical performances. The present study was carried out with a view to highlighting, for the benefit of specialists in medicine and pharmacy, the possibility of achieving and purchasing efficient devices that might be used in the quality control of medicines, as well as in studying and monitoring diseases associated with these amino acids.


Subject(s)
Biosensing Techniques/instrumentation , Electrochemical Techniques/methods , Molecular Imprinting/methods , Molecularly Imprinted Polymers/chemistry , Phenylalanine/analysis , Tryptophan/analysis , Tyrosine/analysis , Amino Acids/analysis , Polymers/chemistry
15.
Biosens Bioelectron ; 203: 114018, 2022 May 01.
Article in English | MEDLINE | ID: covidwho-1648431

ABSTRACT

Multiplex electrochemical biosensors have been used for eliminating the matrix effect in complex bodily fluids or enabling the detection of two or more bioanalytes, overall resulting in more sensitive assays and accurate diagnostics. Many electrochemical biosensors lack reliable and low-cost multiplexing to meet the requirements of point-of-care detection due to either limited functional biosensors for multi-electrode detection or incompatible readout systems. We developed a new dual electrochemical biosensing unit accompanied by a customized potentiostat to address the unmet need for point-of-care multi-electrode electrochemical biosensing. The two-working electrode system was developed using screen-printing of a carboxyl-rich nanomaterial containing ink, with both working electrodes offering active sites for recognition of bioanalytes. The low-cost bi-potentiostat system (∼$80) was developed and customized specifically to the bi-electrode design and used for rapid, repeatable, and accurate measurement of electrochemical impedance spectroscopy signals from the dual biosensor. This binary electrochemical data acquisition (Bi-ECDAQ) system accurately and selectively detected SARS-CoV-2 Nucleocapsid protein (N-protein) in both spiked samples and clinical nasopharyngeal swab samples of COVID-19 patients within 30 min. The two working electrodes offered the limit of detection of 116 fg/mL and 150 fg/mL, respectively, with the dynamic detection range of 1-10,000 pg/mL and the sensitivity range of 2744-2936 Ω mL/pg.mm2 for the detection of N-protein. The potentiostat performed comparable or better than commercial Autolab potentiostats while it is significantly lower cost. The open-source Bi-ECDAQ presents a customizable and flexible approach towards addressing the need for rapid and accurate point-of-care electrochemical biosensors for the rapid detection of various diseases.


Subject(s)
Biosensing Techniques , COVID-19 , Biosensing Techniques/methods , COVID-19/diagnosis , Electrochemical Techniques/methods , Electrodes , Humans , Nucleocapsid Proteins , SARS-CoV-2
16.
Dalton Trans ; 51(5): 2094-2104, 2022 Feb 01.
Article in English | MEDLINE | ID: covidwho-1631403

ABSTRACT

In this study, a novel porphyrin-based porous organic polymer (POP) was constructed using 5,10,15,20-tetramine (4-aminophenyl) porphyrin (TAPP) and 5,5'-diformyl-2,2'-bipyridine (DPDD) as organic ligands via a solvothermal method (represented as TAPP-DPDD-POP). Then, it was utilized as a bifunctional scaffold for constructing a sensitive sensing strategy toward the nucleocapsid phosphoprotein (N-gene) of SARS-CoV-2. The obtained TAPP-DPDD-POP is composed of nanospheres with a size of 100-300 nm and possesses a highly conjugated and π-π stacking network. The coexistence of the porphyrin and bipyridine moieties of TAPP-DPDD-POP afforded considerable electrochemical activity and a strong binding interaction toward the SARS-CoV-2 N-gene-targeted antibody and targeted the aptamer strands of the N-gene. The TAPP-DPDD-POP-based aptasensor and immunosensor were manufactured for the sensitive analysis of SARS-CoV-2 N-gene, and exhibited the limit of detection (LOD) of 0.59 fg mL-1 and 0.17 fg mL-1, respectively, within the range of 0.1 fg mL-1 to 1 ng mL-1 of N-gene. The sensing performances of both the TAPP-DPDD-POP-based aptasensor and immunosensor were better than those of existing electrochemical biosensors for analyzing the N-gene, accompanied with excellent stability, high selectivity and reproducibility. The TAPP-DPDD-POP-based aptasensor and immunosensor were then employed to detect the N-gene from various environments, including human serum, river water, and seafoods. This work provides a new method of using an electrochemically active POP to sensitively and selectively analyze SARS-CoV-2 in diverse environments.


Subject(s)
Biosensing Techniques/methods , COVID-19/diagnosis , Coronavirus Nucleocapsid Proteins/analysis , Electrochemical Techniques/methods , Polymers/chemistry , Porphyrins/chemistry , SARS-CoV-2/isolation & purification , COVID-19/virology , Humans , Limit of Detection , Phosphoproteins/analysis , Reproducibility of Results
18.
ACS Appl Mater Interfaces ; 13(42): 49754-49761, 2021 Oct 27.
Article in English | MEDLINE | ID: covidwho-1475248

ABSTRACT

A reliable and sensitive detection approach for SARS-CoV 2 is essential for timely infection diagnosis and transmission prevention. Here, a two-dimensional (2D) metal-organic framework (MOF)-based photoelectrochemical (PEC) aptasensor with high sensitivity and stability for SARS-CoV 2 spike glycoprotein (S protein) detection was developed. The PEC aptasensor was constructed by a plasmon-enhanced photoactive material (namely, Au NPs/Yb-TCPP) with a specific DNA aptamer against S protein. The Au NPs/Yb-TCPP fabricated by in situ growth of Au NPs on the surface of 2D Yb-TCPP nanosheets showed a high electron-hole (e-h) separation efficiency due to the enhancement effect of plasmon, resulting in excellent photoelectric performance. The modified DNA aptamer on the surface of Au NPs/Yb-TCPP can bind with S protein with high selectivity, thus decreasing the photocurrent of the system due to the high steric hindrance and low conductivity of the S protein. The established PEC aptasensor demonstrated a highly sensitive detection for S protein with a linear response range of 0.5-8 µg/mL with a detection limit of 72 ng/mL. This work presented a promising way for the detection of SARS-CoV 2, which may conduce to the impetus of clinic diagnostics.


Subject(s)
Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Metal-Organic Frameworks/chemistry , SARS-CoV-2/chemistry , Spike Glycoprotein, Coronavirus/analysis , Base Sequence , Biosensing Techniques/instrumentation , COVID-19/diagnosis , DNA/chemistry , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Electrodes , Gold/chemistry , Gold/radiation effects , Humans , Immobilized Nucleic Acids/chemistry , Light , Limit of Detection , Metal Nanoparticles/chemistry , Metal Nanoparticles/radiation effects , Pharynx/virology , Photochemical Processes , Porphyrins/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Ytterbium/chemistry
19.
Mikrochim Acta ; 188(8): 284, 2021 08 02.
Article in English | MEDLINE | ID: covidwho-1397013

ABSTRACT

An aptasensor for electrochemical detection of carbendazim is reported with mulberry fruit-like gold nanocrystal (MF-Au)/multiple graphene aerogel (MGA) and DNA cycle amplification. HAuCl4 was reduced by ascorbic acid in a CTAC solution containing KBr and KI and formed trioctahedron gold nanocrystal. The gold nanocrystal underwent structural evolution under enantioselective direction of L-cysteine. The resulting MF-Au shows a mulberry fruit-like nanostructure composed of gold nanocrystals of about 200 nm as the core and many irregular gold nanoparticles of about 30 nm as the shell. The exposure of high-index facets improves the catalytic activity of MF-Au. MF-Au/MGA was used for the construction of an aptasensor for electrochemical detection of carbendazim. The aptamer hybridizes with assistant strand DNA to form duplex DNA. Carbendazim binds with the formed duplex DNA to release assistant strand DNA, triggering one three-cascade DNA cycle. The utilization of a DNA cycle allows one carbendazim molecule to bring many methylene blue-labeled DNA fragments to the electrode surface. This promotes significant signal amplification due to the redox reaction of methylene blue. The detection signal is further enhanced by the catalysis of MF-Au and MGA towards the redox of methylene blue. A differential pulse voltammetric signal, best measured at - 0.32 V vs. Ag/AgCl, increases linearly with the carbendazim concentration ranging from 1.0 × 10-16 to 1.0 × 10-11 M with a detection limit of 4.4 × 10-17 M. The method provides ultrahigh sensitivity and selectivity and was successfully applied to the electrochemical detection of carbendazim in cucumber. This study reports on an ultrasensitive aptasensor for electrochemical detection of carbendazim in cucumber based on mulberry fruit-like gold nanocrystal-multiple graphene aerogel and DNA cycle double amplification.


Subject(s)
Aptamers, Nucleotide/chemistry , Benzimidazoles/analysis , Biosensing Techniques/methods , Carbamates/analysis , DNA/chemistry , Metal Nanoparticles/chemistry , Benzimidazoles/chemistry , Carbamates/chemistry , Cysteine/chemistry , Electrochemical Techniques/methods , Gels/chemistry , Gold/chemistry , Graphite/chemistry , Immobilized Nucleic Acids/chemistry , Limit of Detection , Methylene Blue/chemistry , Oxidation-Reduction
20.
PLoS One ; 16(7): e0251342, 2021.
Article in English | MEDLINE | ID: covidwho-1290172

ABSTRACT

Amperial™ is a novel assay platform that uses immobilized antigen in a conducting polymer gel followed by detection via electrochemical measurement of oxidation-reduction reaction between H2O2/Tetrametylbenzidine and peroxidase enzyme in a completed assay complex. A highly specific and sensitive assay was developed to quantify levels of IgG antibodies to SARS-CoV-2 in saliva. After establishing linearity and limit of detection we established a reference range of 5 standard deviations above the mean. There were no false positives in 667 consecutive saliva samples obtained prior to 2019. Saliva was obtained from 34 patients who had recovered from documented COVID-19 or had documented positive serologies. All of the patients with symptoms severe enough to seek medical attention had positive antibody tests and 88% overall had positive results. We obtained blinded paired saliva and plasma samples from 14 individuals. The plasma was analyzed using an EUA-FDA cleared ELISA kit and the saliva was analyzed by our Amperial™ assay. All 5 samples with negative plasma titers were negative in saliva testing. Eight of the 9 positive plasma samples were positive in saliva and 1 had borderline results. A CLIA validation was performed as a laboratory developed test in a high complexity laboratory. A quantitative non-invasive saliva based SARS-CoV-2 antibody test was developed and validated with sufficient specificity to be useful for population-based monitoring and monitoring of individuals following vaccination.


Subject(s)
Antibodies, Viral/immunology , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Saliva/immunology , Antibodies, Viral/analysis , COVID-19/immunology , COVID-19/virology , Electrochemical Techniques/methods , Humans , Immunoglobulin G/analysis , Limit of Detection , SARS-CoV-2/isolation & purification , Saliva/virology
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