Surface plasmon resonance‐enhanced photoelectrochemical immunoassay of prostate‐specific antigen based on BiOCl‐Au heterojunction

Abstract

Taking advantage of the high-efficiency photocurrent response of bismuth oxychloride sensitized with gold nanoparticles (BiOClÀ Au) in combination with the antigen-antibody biological recognition reaction, a convenient photoelectrochemical (PEC) immunoassay (model target: prostate-specific antigen; PSA) has been fabricated. In particular, the enhanced photocurrent response could be attributed to the enhanced optical absorption of visible light from surface plasmon resonance (SPR) effect of gold nanoparticles in the hierarchical structure of BiOCl layered. To realize the biological detection process, an immunoreaction was implemented between target PSA and alkaline phosphatase (ALP)-labeled anti-PSA antibodies. With the formation of ternary sandwich immunocomplex, the carried and loaded ALP catalysed the substrate ascorbic acid 2-phosphate (AAP) to generate ascorbic acid for increasing the photocurrent intensity of BiOClÀ Au/FTO. Under optimum reaction time, the photocurrent peak intensity of BiOClÀ Au/FTO increased with the increasing of target PSA concentration in the range of 0.01 ng/mL to 50 ng/mL with a limit of detection (LOD) down to 2.3 pg/mL. In the photocurrent control experiment, the photocurrent of BiOClÀ Au/FTO was not only higher than that of BiOCl/FTO, but also showed greater changes in photocurrent under the same target PSA concentration. Impressively, the proposed split-type PEC immunoassay was applied to detect PSA concentration in human serum samples, giving acceptable and satisfactory accuracy compared with the gold standard PSA ELISA method.

Progress in Electrochemical Immunosensors with Alkaline Phosphatase as the Signal Label

“…ALP can be integrated into PEC immunoassays as an enzyme unit for signal amplification [ 179 , 180 ]. Generally, enzymatic products such as AA could be in situ produced to act as hole-trapping reagents for the capture of the photogenerated holes (h + ) of photoactive materials, providing electrons to hamper the photogenerated electron–hole recombination and resulting in an increase in the photocurrent signal [ 181 , 182 , 183 , 184 , 185 ]. For example, Yang et al developed a signal-on PEC immunosensor for the detection of M.SssI methyltransfease activity based on the ALP-catalyzed in situ production of AA as an electron donor [ 186 ].…”

Enzyme-linked immunoassay for simultaneous detection of methyl parathion and sibutramine in apple cider vinegar

“…The current primary detection methodologies for methyl parathion and sibutramine are instrumental analytical techniques, including high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE), and immunoassay, exemplied by enzyme-linked immunosorbent assay (ELISA). [10][11][12][13][14] Although instrumental analysis can provide accurate detection of samples, it is only suitable for quantitative analysis in a laboratory setting due to the complex sample preparation, expensive equipment and long detection time. 15 The immunoassay method is characterised by a simple operational procedure, a low detection cost and a rapid detection speed, rendering it an optimal choice for large-scale, rapid detection of samples in the eld.…”

Plasmon-induced nonlinear response on gold nanoclusters

“…[13][14][15] Gold nanostructures are typical plasmonic materials that exhibit an excellent plasmonic response, [16] are easily synthesized [17] and have excellent biocompatibility. [18] Consequently, they have garnered immense attention. By tailoring the size and shape of gold nanostructures, fascinating phenomena can be observed.…”