Development and characterisation of cysteine-based gold electrodes for the electrochemical biosensing of the SARS-CoV-2 spike antigen

Abstract

This article describes three novel electrochemical biosensing platforms developed to determine the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) spike antigen protein using glutaraldehyde, SARS-CoV-2 spike antibody and bovine serum albumin; N,N-dicyclohexyl...

Signal-Enhanced Electrochemical Determination of Quercetin with Poly(chromotrope fb)-Modified Pencil Graphite Electrode in Vegetables and Fruits

“…XPS measurements were fulfilled to acquire more information regarding the characterization of each modification step, and the spectra are given in Figure . C 1s bonds between 283.78 and 286.28 eV belong to the C–C and C–O–C structures . A more than 2-fold increase in the C 1s signal at pCFB/aPGE clearly indicates a carbon-based formation on the surface (i.e., polymer of CFB).…”

“…C 1s bonds between 283.78 and 286.28 eV belong to the C−C and C−O− C structures. 45 A more than 2-fold increase in the C 1s signal at pCFB/aPGE clearly indicates a carbon-based formation on the surface (i.e., polymer of CFB). O 1s bonds between 531.88 and 532.08 eV correspond to the aliphatic C−O−C structures, and the increase of the O 1s peak at 531.88 eV for aPGE results from the activation procedure of the bare PGE.…”

A novel label-free electrochemical immunosensor for the detection of heat shock protein 70 of lung adenocarcinoma cell line following paclitaxel treatment using l-cysteine-functionalized Au@MnO2/MoO3 nanocomposites

“…EIS spectra are typically divided into two regions: the high-frequency region (represented by a semicircular curve) and the low-frequency region (represented by the slopes of straight lines known as Warburg impedance). 49 The diameter of the semicircle represents the charge transfer resistance ( R ct ) and is related to the starting point of the semicircular curve, which corresponds to the solution resistance ( R s ) between the electrode and the electrolyte solution. 49 However, fitting EIS data involves using an appropriate equivalent circuit, and in this case, the Randles equivalent circuit is composed of four components, including (i) charge transfer resistance ( R ct ), (ii) Warburg impedance ( Z W ), (iii) solution resistance ( R s ), and (iv) constant phase element (CPE), 50 as shown in Fig.…”

“…The introduction of l -cysteine molecules improved the charge transfer capability by interacting with the negatively charged [Fe(CN) 6 ] 3− . 49 Additionally, the formation of an active ester intermediate during the reaction between EDC and NHS could also improve the electrochemical activity and charge transfer ability. 48 The R ct -value of antiHSP70/EN-LC/Au@MnO 2 /MoO 3 /SPE was increased to 1.74 kΩ when the anti-HSP70 was immobilized on the electrode surface.…”

Diagnostic techniques for critical respiratory infections: Update on current methods

“…While certain electrochemical sensors have been proposed and are in the works. These sensors identify specific biomarkers or antigens linked with COVID viruses and the detected signal is analysed and interpreted to determine the existence or concentration of SARS-CoV-2-associated biomarkers [ [52] , [53] , [54] , [55] ].

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