Split-Type Electrochemical Immunoassay System Triggering Ascorbic Acid-Mediated Signal Magnification Based on a Controlled-Release Strategy

Abstract

This research put forward a novel split-type electrochemical (EC) immunosensor which integrated the controlled-release strategy with EC detection for application in the field of biosensing. Concretely, ascorbic acid (AA) was packaged in a cadmium sulfide (CdS)-capped spherical mesoporous bioactive glass (SBG) nanocarrier (SBGCdS) on account of encapsulation technology. To reduce the complexity of the bioanalysis, the detection antibody-labeled SBGCdS–AA bioconjugate was applied in a 96-well microplate for the immunoreaction process, which is independent of the EC determination procedure. Thus, the immune interference and steric hindrance caused by the accumulation of nanomaterials on the electrode could be minimized. Subsequently, AA was released efficiently via the destruction effect of dithiothreitol on the disulfide bond. In addition, for the as-prepared FcAI/l-Cys/gold nanoparticles (GNPs)/porous BiVO4 (p-BVO)/ITO EC sensing platform in the detection solution, the synergetic catalysis of Fc and GNPs/p-BVO toward the oxidation of the released AA could be realized, which triggered AA-mediated significant signal magnification throughout this study. In particular, p-BVO with an ordered nanoarray structure could accelerate the electron transfer to assist in sensitivity improvement of this system. This novel biosensor was capable of assaying the neuron-specific enolase (NSE) biomarker sensitively, from which a linear range of 0.001–100 ng/mL was derived along with a low detection limit of 1.08 pg/mL. An innovative way could be paved in the bioanalysis of NSE and other biomarkers.

Designing Triangular Silver Nanoplates with GSH/GSSG Surface Mixed States as Novel Nanoparticle-based Redox Mediators for Electrochemical Biosensing

“…Herein, the EC impedance spectroscopy (EIS) test (Figure C) was applied to explore the designed Tri-Ag NPs TSC–GSH/GSSG NRMs and characterize the assembly process of the proposed EC sensing interface. , It could be observed that the semicircle domain of GCE/Nafion (curve a), GCE/Tri-Ag NPs TSC /Nafion (curve b), GCE/Tri-Ag NPs TSC–GSH /Nafion (curve c), and GCE/Tri-Ag NPs TSC–GSH/GSSG /Nafion (curve d) gradually expanded. Notably, there was an increase in the impedance of the Tri-Ag NPs TSC after being partially replaced by GSH.…”

Silver nanoparticles in electrochemical immunosensing and the emergence of silver–gold galvanic exchange detection

“…Linear anodic stripping voltammetry (LASV) 42,74,[128][129][130] and differential pulse anodic stripping voltammetry (DPASV) 66,[131][132][133] are the most prevalent techniques used in the literature for the final Ag oxidation step. However, some studies have used square wave anodic stripping voltammetry (SWASV) 36,40,55 and cyclic voltammetry (CV). 25,38,39 LASV is the most prevalent among these techniques because of its simplicity.…”

Direct detection of neuron-specific enolase using a spectrometer-free colorimetric plasmonic biosensor

“…21 Therefore, the NSE is one of the important biomarkers to be monitored. 22 Detection of NSE has been reported using various biosensing schemes, including surface plasmon resonance (SPR) spectroscopy, 23 surface plasmon-enhanced uorescence (SPF), 24,25 uorescence, 26 electrochemistry, [27][28][29] and photoelectrochemistry. 30,31 Nevertheless, most of the sensing methods rely on the development of nanomaterials that enhance or produce the sensor signals to detect NSE at its clinical threshold value.…”