Abstract:This work describes a sensitive voltammetric immunosensor for label‐free electroanalysis of the prostate specific antigen (PSA), the main biomarker of prostate cancer. A gold electrode was firstly modified with the optimum self‐assembled monolayer (SAM), 1,6‐hexanedithiol, followed by the subsequent adsorption of gold nanoparticles (AuNPs) and, then, the monoclonal antibody to recognize PSA was immobilized. The influence of the most significant experimental variables (SAM type and incubation time, AuNPs deposi… Show more
“…5 A shows the representative CV obtained to the Np detection with concentration ranging from 30 to 580 μg mL −1 . The CV data showed a dependence from the Np concentration added and the electrochemical response of the probe, indicating an inert kinetic barrier for the electron-transfer as the Np concentration rises, that is likely related to the antigen-antibody immunocomplex formation, as it acts as an insulating on the device surface [ [35] , [36] , [37] ]. Fig.…”
Simple, low-cost, and sensitive new platforms for electrochemical immunosensors for virus detection have been attracted attention due to the recent pandemic caused by a new type of coronavirus (SARS-CoV-2). In the present work, we report for the first time the construction of an immunosensor using a commercial 3D conductive filament of carbon black and polylactic acid (PLA) to detect Hantavirus Araucaria nucleoprotein (Np) as a proof-of-concept. The recognition biomolecule was anchored directly at the filament surface by using
N
-(3-Dimethylaminopropyl)-
N
′-ethylcarbodiimide hydrochloride and
N
-Hydroxysuccinimide (EDC/NHS). Conductive and non-conductive composites of PLA were characterized using thermal gravimetric analysis (TGA), revealing around 30% w/w of carbon in the filament. Morphological features of composites were obtained from SEM and TEM measurements. FTIR measurement revealed that crosslinking agents were covalently bonded at the filament surface. Electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for the evaluation of each step involved in the construction of the proposed immunosensor. The results showed the potentiality of the device for the quantitative detection of Hantavirus Araucaria nucleoprotein (Np) from 30 μg mL
−1
to 240 μg mL
−1
with a limit of detection of 22 μg mL
−1
. Also, the proposed immunosensor was applied with success for virus detection in 100x diluted human serum samples. Therefore, the PLA conductive filament with carbon black is a simple and excellent platform for immunosensing, which offers naturally carboxylic groups able to anchor covalently biomolecules.
“…5 A shows the representative CV obtained to the Np detection with concentration ranging from 30 to 580 μg mL −1 . The CV data showed a dependence from the Np concentration added and the electrochemical response of the probe, indicating an inert kinetic barrier for the electron-transfer as the Np concentration rises, that is likely related to the antigen-antibody immunocomplex formation, as it acts as an insulating on the device surface [ [35] , [36] , [37] ]. Fig.…”
Simple, low-cost, and sensitive new platforms for electrochemical immunosensors for virus detection have been attracted attention due to the recent pandemic caused by a new type of coronavirus (SARS-CoV-2). In the present work, we report for the first time the construction of an immunosensor using a commercial 3D conductive filament of carbon black and polylactic acid (PLA) to detect Hantavirus Araucaria nucleoprotein (Np) as a proof-of-concept. The recognition biomolecule was anchored directly at the filament surface by using
N
-(3-Dimethylaminopropyl)-
N
′-ethylcarbodiimide hydrochloride and
N
-Hydroxysuccinimide (EDC/NHS). Conductive and non-conductive composites of PLA were characterized using thermal gravimetric analysis (TGA), revealing around 30% w/w of carbon in the filament. Morphological features of composites were obtained from SEM and TEM measurements. FTIR measurement revealed that crosslinking agents were covalently bonded at the filament surface. Electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for the evaluation of each step involved in the construction of the proposed immunosensor. The results showed the potentiality of the device for the quantitative detection of Hantavirus Araucaria nucleoprotein (Np) from 30 μg mL
−1
to 240 μg mL
−1
with a limit of detection of 22 μg mL
−1
. Also, the proposed immunosensor was applied with success for virus detection in 100x diluted human serum samples. Therefore, the PLA conductive filament with carbon black is a simple and excellent platform for immunosensing, which offers naturally carboxylic groups able to anchor covalently biomolecules.
“…The PSA-BSA|Ab|TGA-OsTe 2 QD|PPy|GCE for 10 ng/mL PSA (curve e) showed a decrease in current due to hindrance in electron transfer as a result of the capture of the PSA by its antibody. It is important to note that the capture promoted a slight shift of the reduction peak due to the immunosensor surface modification [54].…”
Section: Electrochemistry Of the Immunosensor Platformmentioning
Prostate cancer is a dominant global threat to society. It affects nearly 4000 men in South Africa annually, making it the second most threatening cancerous disease after lung cancer. A potential serological biomarker to monitor early diagnosis of prostate cancer is prostate specific antigen (PSA). We used the PSA biomarker in our work to develop an extremely sensitive electrochemical immunosensor to achieve low detection limits. The fabrication steps followed with the combination of thioglycolic acid capped osmium telluride quantum dots (TGA-OsTe2QD)-polypyrrole (PPy) nanocomposite and prostate specific antigen modified on a glassy carbon electrode. The UV-Vis signatures of TGA-OsTe2QD-PPy showed an absorption band at 262 nm which is attributed to the PPy and TGA-OsTe2QD composite. This band corresponds to the energy band gap of 4.4 and 5.4 eV. The CV responses of BSA|Ab|TGA-OsTe2QD|PPy|GCE modified electrode to prostate specific antigen (PSA) was studied within a range of 0–16 ng/mL PSA that was linear, herein referred to as liner range (LR), which produced a limit of detection (LOD) value of 0.36 ng/mL PSA. The values of the immunosensor’s calibration parameters (LR and LOD) make them suitable for real sample application, due to their coverage of the PSA concentration range (0–14 ng/mL) that is of clinical importance.
“…17 In another report on the detection of prostate-specific antigen (PSA), [Fe(CN) 6 ] 3−/4− was used in a label-free voltammetric immunosensor based on SAM of 1,6-hexanedithiol gold electrode, followed by adsorption of AuNPs before being immobilized with a monoclonal antibody. 18 [Fe(CN) 6 ] 3−/4− has also been used in impedance sensing based on allergen-antibody interaction at nanogold-modified GC electrode. 19 Meanwhile, in the indirect electrochemical immunosensor of the labelled assay, the analyte is sandwiched between the capture agent and labelled agent, called a sandwich-type immunosensor.…”
Strongyloidiasis is an intestinal helminth infection caused by Strongyloides stercoralis. Early detection of this infection in immunocompromised patients is crucial to avoid severe complications and fatality. Herein, we present the potential application of electrodeposited AuNP-film in developing a label-free electrochemical immunosensor for strongyloidiasis using our synthesized monoclonal antibody. Layer-upon-layer attachment of Strongyloides monoclonal recombinant antibody protein (rMAb23) onto AuNP-film was constructed, utilizing a thiol linker via a self-assembly monolayer (SAM) technique. The modified electrode was utilized to detect S. stercoralis recombinant NIE (rNIE) protein. Each successful modification step was tested in a 10 mM [Fe(CN)6]3-/4- redox couple solution utilizing cyclic voltammetric (CV) and electrochemical impedance spectroscopic (EIS) techniques. The developed immunosensor required 20 minutes of incubation with an rNIE solution. Specificity study showed no cross-reaction with three other helminth recombinant proteins. Utilizing EIS measurements for a concentration series of rNIE protein in phosphate-buffered saline, ranging from 1 µg/mL to 10 µg/mL, we obtained a detection limit of 0.182 µg/mL. The electrochemical immunosensor was also successfully used to analyze serum samples of individuals with strongyloidiasis and healthy people. The results indicate that the immunosensor might offer an excellent diagnostic capability and a rapid and sensitive antigen detection of strongyloidiasis.
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