Design and Implementation of Environmental Monitoring System Using Photoelectric Wireless Sensor Network

Abstract

Photoelectrochemical (PEC) sensing is a light-induced electron transfer sensing method based on photoelectric signal conversion to represent the electrode/solution interface. The analysis method is easily disturbed by environmental factors such as light intensity, which reduces the detection accuracy. PEC biosensor with sunlight as the light source is designed. CC2530 RF hardware module and Zstack software protocol stack produced by TI company are adopted to establish PEC wireless sensor network (WSN) for farmland environment detection. 5G-DTU module is selected to realize the remote data transmission between the PEC WSN and remote server. The data exchange is carried out through a 5G mobile communication network. The farmland environment monitoring adopts B/S architecture. The types of all PEC sensors need to be selected and the hardware circuit module is designed. The corresponding interface adopts a unified standard 485 bus communication interface to facilitate the data reading of the sensor. In the experiment, the designed PEC sensor can distinguish between carbon nitride nanosheets (CNNS) and nitrogen fossil graphene loaded silver/TiO2 (Ag/TiO2/D3NGH) by changing the bias potential, and the sensor can work in unstable sunlight. The photocurrent of anode and cathode of the PEC sensor increases with the increase of sunlight intensity, and the photocurrent ratio remains constant with the further increase of the concentration of double electrodes (CNNS, Ag/TiO2/D3NGH). In the field mold test, the designed PEC sensor shows good selectivity for aflatoxin B1 (AFB1), and the AFB1 is recovered from bean products in the field, with a recovery rate of more than 95%, which proves that the photoelectric monitoring system can accurately measure and analyze the field mold.