Choline sensing based on enhanced chemiluminescence of luminol-O2/PDTC@AuNPs system using a smartphone imaging technique

Abstract

Herein, we have proposed a simple, quick, cost-effective, and enhanced chemiluminescence (eCL) imaging method capitalized on the luminol-O2/PDTC@AuNPs CL probe based on a smartphone as a portable hand-held CL detector for the sensitive and selective detection of choline (Chol) in standard and human serum samples. The luminol-O2 CL reagent is integrated with the chain-like Propane-1,3-dithiol (PDT) crosslinked gold (Au) nanoparticles (PDTC@AuNPs) and acts as a catalyst to obtain a visible and efficient CL probe (luminol-O2/PDTC@AuNPs). PDTC@AuNPs is prepared by chemical reduction of Au-salt followed by simple mixing of AuNPs and PDT and is successfully characterized by various characterization techniques. The PDTC@AuNPs facilitate the production of reactive species (·O2−, 1O2, ·OH) and impart good catalytic behavior in the luminol-O2 CL reaction, thereby greatly enhancing the CL signal compared to AuNPs. A mechanism for these observations is thoroughly investigated. Further, based on the enhancement property of luminol-O2/PDTC@AuNPs towards Chol's catalytic product (H2O2), an eCL method has been proposed for detecting Chol. Under optimal conditions, the as-proposed eCL imaging probe exhibits a linear increase in CL imaging response in a broad range from 0.001 mM to 1.2 mM standard choline concentrations, with the LOD 0.001 mM. Finally, we observed a recovery of 94.0 % to 108.0 % in human serum samples of healthy individuals and pregnant women. © 2025 Elsevier B.V.