Visible-light-driven renewable photoelectrochemical/synchronous visualized sensing platform based on Ni:FeOOH/BiVO4 photoanode and enzymatic cascade amplification for carcinoembryonic antigen detection

Abstract

A renewable photoelectrochemical/synchronous visualized sensing platform with two functional cells, named sensing and electrochromic cells, was developed for ultrasensitive detection of carcinoembryonic antigen (CEA). For achieving a boosted photocurrent intensity, the Ni:FeOOH/BiVO4 nanocomposites were engineered and served as the photoanode materials, which were then combined with the cathode material Prussian blue (PB) to form the sensing cell. Through the sandwich-type immunoreaction and enzymatic cascade amplification, the carried GOx could catalyse the decomposition of glucose to produce H2O2, leading to improvement of electron transfer efficiency of Ni:FeOOH/BiVO4 under the light irradiation and accompanying by the PB reduced to Prussian white (PW). By combining digital multimeter (DMM)-joined circuit to collect photocurrents with PB electrochromic indicator, ultrasensitive and naked eye visual detection of CEA was realized synchronously. On the electrochromic cell, laccase as the biocathode enabled PW back to the original PB state through the biocatalyzing oxygen reduction of the laccase, gaining an updatable sensing platform. Under the optimal conditions, the bimodal biosensor shows acceptable dynamic working range for CEA from 1 pg·mL−1 to 90 ng·mL−1 with a detection limit (LOD) of 0.35 pg mL−1. Meanwhile, it also has great potential applications in real sample analysis.