Metal-free Photochemically Mediated ATRP for Ultrasensitive Quantification of CYFRA 21-1 for Detection of Early Stage Non-Small Cell Lung Cancer

A convenient electrochemiluminescence (ECL) biosensor for sensitive detecting CYFRA 21-1 via metal-free photoinduced atom transfer radical polymerization (photo-ATRP) strategy was constructed for the first time. The CYFRA 21-1 antigen was modified on the Au electrode surface by constructing a sandwich type antibody-antigen-antibody immune system, which could achieve high selectivity through twice specific recognition. Photo-ATRP, which can avoid the use of heavy metal catalysts, and control the polymerization reaction by turning the light on and off, was activated by the photoredox catalyst Esion Y (EY) upon 470 nm blue light (24 V/15 W) irradiation. Whereafter, a large number of luminol binding sites were generated, which resulted in significant signal amplification. Under the optimal experimental conditions, the biosensor displayed an ideal linear relationship in the range from 10 fg ml(-1) to 1 ng ml(-1) with a low detection limit of 5.8 fg ml(-1), which can realize the trace detection of CYFRA 21-1. Furthermore, the prepared ECL biosensor exhibited specific selectivity, outstanding stability and reproducibility. This ECL sensing systems highlighted the advances of using metal-free photo-ATRP signal amplification strategy in the developments of highly efficient and environmentally friendly immunosensors for CYFRA 21-1 detection. (C) 2022 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.