4.2. Apparatus
The photoelectrochemical test system (PEC1000, Beijing Perfectlight Technology Co., Ltd., China), equipped with a Xe lamp (PLS-FX300HU, Beijing Perfectlight Technology Co., Ltd., China) and an electrochemical workstation (CHI 760E, Shanghai Chenhua Instrument Co., Ltd., China), was employed for PEC measurements. The base SPE electrodes were purchased from Shenzhen Yick Xin Technology R&D Co., Ltd. (Shenzhen, China). The working electrode (2 mm diameter) was composed of vertical graphene with surface-deposited Au NPs. The reference electrode employed was Ag/AgCl, and the counter electrode consisted of carbon paste.
SEM (SU-70, Hitachi Co., Tokyo, Japan) was utilized to perform morphological characterization of the electrode. Energy dispersive spectroscopy (EDS; EX-250, Horiba, Kyoto, Japan) was employed to characterize the distribution of chemical elements at the electrode interface. A surface analysis system (AXIS Ultra-DLD, Kratos Analytical, Manchester, U.K.) equipped with monochromatic Al Kα (1486.6 eV) radiation was utilized for conducting XPS analysis. The automated robot (Shennong-1, Shenzhen Metasensing Technology Co., Ltd., China) was used for sewage sampling, enrichment, concentration, nucleic acid extraction, and reverse transcription.