Persistent luminescence nanorods-based autofluorescence-free biosensor for prostate-specific antigen detection.

Persistent luminescent nanoparticles (PLNPs) are a class of materials with excellent optical properties, which can continue to emit light for a long time after removing the excitation light source. This feature enables PLNPs to be used for development of biological detection modes without autofluorescence background. In this study, we prepared Zn2GeO4: Mn2+, Pr3+ (ZGOMP) nanorods through a one-pot hydrothermal method. Using the pH-responsive luminescence behavior of ZGOMP, we developed an autofluorescence-free biosensor using ZGOMP as a probe and gluconic acid as a quencher to detect prostate-specific antigen (PSA). Hybridization chain reaction (HCR) and magnetic separation system were introduced in the design to achieve efficient signal amplification. Under the optimal conditions, the as-designed autofluorescence-free sensing platform showed high selectivity, and showed a good luminescence response to PSA within the linear range of 0.001-10 ng/mL at a detection limit of 0.64 pg/mL. The excellent analytical performance shows that the current strategy provides an effective platform for clinical sample analysis.

Ultrasensitive photoelectrochemical immunoassay for prostate-specific antigen based on silver nanoparticle-triggered ion-exchange reaction with ZnO/CdS nanorods.

Prostate-specific antigen (PSA), a glycoprotein that is most likely to cause prostate cancer, has attracted widespread attention in recent years due to its increasing threat to people's lives and health. Herein, we developed a new signal-amplified photoelectrochemical (PEC) immunosensing method for quantitative monitoring of the target PSA based on the ion-exchange reaction for the in situ formation of ZnO/CdS/Ag2S nanohybrids triggered by the as-released silver ions (Ag+) from silver nanolabels. Initially, the introduction of a target PSA caused the formation of a sandwich immunocomplex in an anti-PSA capture antibody (cAb)-coated microplate with the help of a silver nanoparticle-labeled detection antibody (AgNPs-dAb). Thereafter, the introduced AgNPs were dissolved with acid to release numerous silver ions. In this regard, an ion-exchange reaction occurred between the silver ions and ZnO/CdS nanorods on the photosensitive electrode, thus producing ZnO/CdS/Ag2S nanohybrids to generate a relatively strong photocurrent. Under optimal conditions, the ion-exchange reaction-based PEC immunoassay exhibited a good linear range of 0.05-50 ng mL-1 and allowed the detection of the target PSA at a concentration as low as 0.018 ng mL-1. In addition, the PEC immunoassay displayed satisfactory repeatability, high specificity, and acceptable method accuracy. Importantly, the ion-exchange reaction-based PEC immunoassay provides a new perspective for the detection of other disease-related biomarkers by controlling the corresponding antibodies.