A sandwich-type photoelectrochemical immunosensor strategy based on anti-human IgE@ZnS QD-activated amplifier for highly sensitive IgE detection

Abstract

IgE detection in allergy-related diseases is still a challenge, and the existing clinical detection strategies are expensive and time-consuming, which are difficult to meet the clinical needs. Photoelectrochemical methods, which are developing rapidly, are widely used in the field of biomolecular marker detection because of their reliable performance, convenient operation and low cost. In this study, a highly sensitive photoelectrochemical immunosensor based on zinc sulfide quantum dots (ZnS QDs) modification was developed for IgE detection. ZnS QDs synthesized by hydrothermal method have strong photoelectrochemical reaction ability, and Anti-IgE@ZnS QDs was used as a probe to construct a sandwich sensor on a CS/Au nanoparticle-modified ITO slide. The sensor utilizes the excellent conductivity of ZnS QDs and Au NPs to exhibit good photoelectrochemical (PEC) performance in I₃⁻/I⁻ electrolytes without the need for biotoxic reagents. The linear range of IgE detection is from 1 ng mL⁻¹ to 1×10⁵ ng mL⁻¹, with a limit of detection of 6.12 ng mL⁻¹ and a limit of quantification of 18.5 ng mL⁻¹. The sensor offers excellent stability, selectivity, and reproducibility for IgE detection. The sensor provides a new method for IgE detection, and its photoelectrochemical platform provides a reference strategy for the detection of other biomolecules.