Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 684
Filter
1.
Crit Care ; 26(1): 353, 2022 11 14.
Article in English | MEDLINE | ID: covidwho-2139378
2.
Biosens Bioelectron ; 218: 114761, 2022 Dec 15.
Article in English | MEDLINE | ID: covidwho-2130158

ABSTRACT

Miniaturization of biosensors has become an imperative demand because of its great potential in in vivo biomarker detection and disease diagnostics as well as the point-of-care testing for coping with public health crisis, such as the coronavirus disease 2019 pandemic. Here, we present an ultraminiature optical fiber-tip biosensor based on the plasmonic gold nanoparticles (AuNPs) directly printed upon the end face of a standard multimode optical fiber at visible light range. An in-situ precision photoreduction technology is developed to additively print the micropatterns of size-controlled AuNPs. The AuNPs reveal distinct localized surface plasmon resonance, whose peak wavelength provides an ideal spectral signal for label-free biodetection. The fabricated optical fiber-tip plasmonic biosensor can not only detect antibody, but also test SARS-CoV-2 mimetic DNA sequence at the concentration level of 0.8 pM. Such an ultraminiature fiber-tip plasmonic biosensor offers a cost-effective biodetection technology for a myriad of applications ranging from point-of-care testing to in vivo diagnosis of stubborn diseases.


Subject(s)
Biosensing Techniques , COVID-19 , Metal Nanoparticles , Humans , Optical Fibers , Gold , SARS-CoV-2 , COVID-19/diagnosis , Surface Plasmon Resonance
3.
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
4.
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
5.
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
6.
Biosensors (Basel) ; 12(11)2022 Nov 08.
Article in English | MEDLINE | ID: covidwho-2109935

ABSTRACT

Worldwide infection due to SARS-CoV-2 revealed that short-time and extremely high-sensitivity detection of nucleic acids is a crucial technique for human beings. Polymerase chain reactions have been mainly used for the SARS-CoV-2 detection over the years. However, an advancement in quantification of the detection and shortening runtime is important for present and future use. Here, we report a rapid detection scheme that is a combination of nucleic acid amplification and a highly efficient fluorescence biosensor, that is, a metasurface biosensor composed of a pair of an all-dielectric metasurface and a microfluidic transparent chip. In the present scheme, we show a series of proof-of-concept experimental results that the metasurface biosensors detected amplicons originating from attomolar SARS-CoV-2 nucleic acids and that the amplification was implemented within 1 h. Furthermore, this detection capability substantially satisfies an official requirement of 100 RNA copies/140 µL, which is a criterion for the reliable infection tests.


Subject(s)
Biosensing Techniques , COVID-19 , Nucleic Acids , Humans , SARS-CoV-2 , COVID-19/diagnosis , Sensitivity and Specificity , Nucleic Acid Amplification Techniques/methods , Molecular Diagnostic Techniques/methods
7.
Anal Chem ; 94(45): 15908-15914, 2022 Nov 15.
Article in English | MEDLINE | ID: covidwho-2106293

ABSTRACT

The current CRISPR/Cas12a-based diagnostic techniques focus on designing the crRNA or substrate DNA elements to indirectly switch the trans-cleavage activity of Cas12a responsive to target information. Here, we propose the use of an allosteric DNA probe to directly regulate the trans-cleavage activity of Cas12a and present a method for sensing different types of analytes. An allosteric inhibitor probe is rationally designed to couple the target recognition sequence with the inhibitory aptamer of the CRISPR/Cas12a system and enables binding to a specific target to induce the change of conformation, which leads to the loss of its inhibitory function on Cas12a. As a result, the structure-switchable probe can regulate the degree of activity of Cas12a depending on the dose of target. Scalability of our strategy can be achieved by simply replacing the loop domain with different target recognition sequences. The proposed method was validated by detecting adenosine triphosphate and let-7a, giving the detection limits of 490 nM and 26 pM, respectively, and showing an excellent specificity. We believe that this work exploits a viable approach to use the inhibitory aptamer of Cas12a as a regulatory element for biosensing purposes, enriching the arsenal of CRISPR/Cas12a-based methods for molecular diagnostics and spurring further development and application of aptamers of the CRISPR/Cas system.


Subject(s)
Biosensing Techniques , CRISPR-Cas Systems , CRISPR-Cas Systems/genetics , DNA Cleavage , DNA/genetics , Oligonucleotides
8.
Anal Chim Acta ; 1232: 340442, 2022 Nov 01.
Article in English | MEDLINE | ID: covidwho-2104217

ABSTRACT

In the present work, we report an innovative approach for immunosensors construction. The experimental strategy is based on the anchoring of biological material at screen-printed carbon electrode (SPE) modified with electrodeposited Graphene Quantum Dots (GQD) and polyhydroxybutyric acid (PHB). It was used as functional substract basis for the recognition site receptor-binding domain (RBD) from coronavirus spike protein (SARS-CoV-2), for the detection of Anti-S antibodies (AbS). SEM images and EDS spectra suggest an interaction of the protein with GQD-PHB sites at the electrode surface. Differential pulse voltametric (DPV) measurements were performed before and after incubation, in presence of the target, shown a decrease in voltametric signal of an electrochemical probe ([Fe(CN)6]3/4-). Using the optimal experimental conditions, analytical curves were performed in PBS and human serum spiked with AbS showing a slight matrix effect and a relationship between voltametric signal and AbS concentration in the range of 100 ng mL-1 and 10 µg mL-1. The selectivity of the proposed sensor was tested against yellow fever antibodies (YF) and the selective layer on the electrode surface did not interact with these unspecific antibodies. Eight samples of blood serum were analyzed and 87.5% of these total investigated provided adequate results. In addition, the present approach showed better results against traditional EDC/NHS reaction with enhancements in time and the possibility to develop an immunosensor in a single drop, since the proteins can be anchored prior to the electrode modification step.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Quantum Dots , Humans , Graphite/chemistry , Quantum Dots/chemistry , SARS-CoV-2 , Electrochemical Techniques/methods , Spike Glycoprotein, Coronavirus , Limit of Detection , Immunoassay , Electrodes , Carbon/chemistry , Antibodies
9.
Mikrochim Acta ; 189(12): 443, 2022 11 09.
Article in English | MEDLINE | ID: covidwho-2103917

ABSTRACT

The epidemic of infectious diseases caused by contagious pathogens is a life-threatening hazard to the entire human population worldwide. A timely and accurate diagnosis is the critical link in the fight against infectious diseases. Aptamer-based biosensors, the so-called aptasensors, employ nucleic acid aptamers as bio-receptors for the recognition of target pathogens of interest. This review focuses on the design strategies as well as state-of-the-art technologies of aptasensor-based diagnostics for infectious pathogens (mainly bacteria and viruses), covering the utilization of three major signal transducers, the employment of aptamers as recognition moieties, the construction of versatile biosensing platforms (mostly micro and nanomaterial-based), innovated reporting mechanisms, and signal enhancement approaches. Advanced point-of-care testing (POCT) for infectious disease diagnostics are also discussed highlighting some representative ready-to-use devices to address the urgent needs of currently prevalent coronavirus disease 2019 (COVID-19). Pressing issues in aptamer-based technology and some future perspectives of aptasensors are provided for the implementation of aptasensor-based diagnostics into practical application.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , COVID-19 , Communicable Diseases , Humans , COVID-19/diagnosis , Point-of-Care Testing , Communicable Diseases/diagnosis
10.
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
11.
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
12.
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
13.
Opt Express ; 30(22): 40277-40291, 2022 Oct 24.
Article in English | MEDLINE | ID: covidwho-2089309

ABSTRACT

We conceptualized and numerically investigated a photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) sensor for rapid detection and quantification of novel coronavirus. The plasmonic gold-based optical sensor permits three different ways to quantify the virus concentrations inside patient's body based on different ligand-analyte conjugate pairs. This photonic biosensor demonstrates viable detections of SARS-CoV-2 spike receptor-binding-domain (RBD), mutated viral single-stranded ribonucleic acid (RNA) and human monoclonal antibody immunoglobulin G (IgG). A marquise-shaped core is introduced to facilitate efficient light-tailoring. Analytes are dissolved in sterile phosphate buffered saline (PBS) and surfaced on the plasmonic metal layer for realizing detection. The 1-pyrene butyric acid n-hydroxy-succinimide ester is numerically used to immobilize the analytes on the sensing interface. Using the finite element method (FEM), the proposed sensor is studied critically and optimized for the refractive index (RI) range from 1.3348-1.3576, since the target analytes RIs fluctuate within this range depending on the severity of the viral infection. The polarization-dependent sensor exhibits dominant sensing attributes for x-polarized mode, where it shows the average wavelength sensitivities of 2,009 nm/RIU, 2,745 nm/RIU and 1,984 nm/RIU for analytes: spike RBD, extracted coronavirus RNA and antibody IgG, respectively. The corresponding median amplitude sensitivities are 135 RIU-1, 196 RIU-1 and 140 RIU-1, respectively. The maximum sensor resolution and figure of merit are found 2.53 × 10-5 RIU and 101 RIU-1, respectively for viral RNA detection. Also, a significant limit of detection (LOD) of 6.42 × 10-9 RIU2/nm is obtained. Considering modern bioassays, the proposed compact photonic sensor will be well-suited for rapid point-of-care COVID testing.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , SARS-CoV-2 , Ligands , Butyric Acid , COVID-19 Testing , RNA, Viral , COVID-19/diagnosis , Gold/chemistry , Immunoglobulin G , Succinimides , Pyrenes , Antibodies, Monoclonal , Esters , Phosphates
14.
ACS Appl Mater Interfaces ; 14(43): 48464-48475, 2022 Nov 02.
Article in English | MEDLINE | ID: covidwho-2087121

ABSTRACT

Rapid and precise serum cytokine quantification provides immense clinical significance in monitoring the immune status of patients in rapidly evolving infectious/inflammatory disorders, examplified by the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. However, real-time information on predictive cytokine biomarkers to guide targetable immune pathways in pathogenic inflammation is critically lacking, because of the insufficient detection range and detection limit in current label-free cytokine immunoassays. In this work, we report a highly sensitive localized surface plasmon resonance imaging (LSPRi) immunoassay for label-free Interleukin 6 (IL-6) detection utilizing rationally designed peptide aptamers as the capture interface. Benefiting from its characteristically smaller dimension and direct functionalization on the sensing surface via Au-S bonding, the peptide-aptamer-based LSPRi immunoassay achieved enhanced label-free serum IL-6 detection with a record-breaking limit of detection down to 4.6 pg/mL, and a wide dynamic range of ∼6 orders of magnitude (values from 4.6 to 1 × 106 pg/mL were observed). The immunoassay was validated in vitro for label-free analysis of SARS-CoV-2 induced inflammation, and further applied in rapid quantification of serum IL-6 profiles in COVID-19 patients. Our peptide aptamer LSPRi immunoassay demonstrates great potency in label-free cytokine detection with unprecedented sensing capability to provide accurate and timely interpretation of the inflammatory status and disease progression, and determination of prognosis.


Subject(s)
Aptamers, Peptide , Biosensing Techniques , COVID-19 , Humans , SARS-CoV-2 , Cytokines/analysis , Interleukin-6 , Immunoassay/methods , Inflammation
15.
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
16.
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
17.
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
18.
Anal Chem ; 94(45): 15553-15557, 2022 Nov 15.
Article in English | MEDLINE | ID: covidwho-2076957

ABSTRACT

Macromolecular association is crucial to many fields in biomedical sciences, including drug development, gene editing, and diagnostics. In particular, protein-protein association and dissociation rate constants are typically determined using surface plasmon resonance systems, which require costly instrumentation and cumbersome procedures (e.g., blocking, washing, and separation). Herein, we demonstrate that protein-binding constants can be readily determined using a real-time biosensing platform facilitated by graphene oxide-modified microwell plates and fluorophore-labeled proteins, where the fluorescent probes remain highly fluorescent during protein association, whereas fluorescent bioprobes that are not associated with their counterparts are quenched by graphene oxide. Binding data of three pairs of proteins were systematically determined employing this single-step platform and compared with those data reported by the suppliers or the literature, suggesting that this approach is comparable and consistent with the existing ones. Such pairs include (i) human immunoglobulin G (H-IgG)-fluorophore-labeled anti-H-IgG, (ii) prostate-specific antigen (PSA)-quantum dot-labeled anti-PSA, and (iii) anti-RBD-fluorophore-labeled SARS-CoV-2 spike receptor-binding domain recombinant protein. We also offer an open-source software that automatically determines the binding kinetics constants of proteins. This Technical Note introduces a simple, yet effective, platform to determine relevant information on protein kinetics, which can be performed using a microwell plate reader and economical materials like graphene oxide. We foresee a new generation of diagnostics based on our affordable protein kinetics analysis.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , Male , SARS-CoV-2 , Kinetics , Fluorescent Dyes , Immunoglobulin G/chemistry
19.
J Med Virol ; 94(12): 5808-5826, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2075068

ABSTRACT

Rapid detection of antibodies during infection and after vaccination is critical for the control of infectious outbreaks, understanding immune response, and evaluating vaccine efficacy. In this manuscript, we evaluate a simple ultrarapid test for SARS-CoV-2 antibodies in COVID-19 patients, which gives quantitative results (i.e., antibody concentration) in 10-12 s using a previously reported nanomaterial-based three-dimensional (3D)-printed biosensing platform. This platform consists of a micropillar array electrode fabricated via 3D printing of aerosolized gold nanoparticles and coated with nanoflakes of graphene and specific SARS-CoV-2 antigens, including spike S1, S1 receptor-binding domain (RBD) and nucleocapsid (N). The sensor works on the principle of electrochemical transduction, where the change of sensor impedance is realized by the interactions between the viral proteins attached to the sensor electrode surface and the antibodies. The three sensors were used to test samples from 17 COVID-19 patients and 3 patients without COVID-19. Unlike other serological tests, the 3D sensors quantitatively detected antibodies at a concentration as low as picomole within 10-12 s in human plasma samples. We found that the studied COVID-19 patients had higher concentrations of antibodies to spike proteins (RBD and S1) than to the N protein. These results demonstrate the enormous potential of the rapid antibody test platform for understanding patients' immunity, disease epidemiology and vaccine efficacy, and facilitating the control and prevention of infectious epidemics.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Metal Nanoparticles , Antibodies, Viral , COVID-19/diagnosis , Gold , Humans , Printing, Three-Dimensional , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
20.
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
SELECTION OF CITATIONS
SEARCH DETAIL