Internal reference self-powered aptasensor for on-site detection of MC-RR used sunlight as light source and CoMoS4 hollow nanospheres as photocathode

Abstract

As a liver toxin, long-term exposure of microcystin-arginine-arginine (MC-RR) is harmful to the ecological environment and human health, so it is necessary to realize on-site detection of MC-RR. The self-powered sensor has enormous potential for on-site detection in battery-free devices. However, due to the low photoelectric conversion efficiency and poor anti-interference ability to environmental fluctuation, the field detection of self-powered sensor is limited. Herein, we tackled above problems according to the following two aspects. For one hand, CoMoS4 hollow nanospheres modified internal reference electrode was arranged in the self-powered sensor, which effectively avoided the influence of unstable sunlight caused by different space, time, weather and other factors. For the other hand, dual-photoelectrode could absorb and convert sunlight, so as to improve the solar capture and energy utilization, and realized the sunlight instead of traditional external light source (Xenon lamp or LED, etc.). This method effectively simplified the sensing device and solved the interference of environment in on-site detection. In addition, multimeter was used to measure the output voltage instead of electrochemical workstation, achieving the purpose of portability. This work established a sunlight-driven internal reference self-powered sensor with miniaturization, portability and anti-interference to realize MC-RR on-site monitoring in lake water.