Abstract
The design and construction of a visible light-driven photoelectrochemical (PEC) device is described based on a CdSe-Co(3)O(4)@TiO(2) nanoflower (NF). Moreover, an application to the ultrasensitive detection of viruses, such as hepatitis E virus (HEV), HEV-like particles (HEV-LPs), and SARS-CoV-2 spike protein in complicated lysate solution, is demonstrated. The photocurrent response output of a PEC device based on CdSe-Co(3)O(4)@TiO(2) is enhanced compared with the individual components, TiO(2) and CdSe-Co(3)O(4). This can be attributed to the CdSe quantum dot (QD) sensitization effect and strong visible light absorption to improve overall system stability. A robust oxygen-evolving catalyst (Co(3)O(4)) coupled at the hole-trapping site (CdSe) extends the interfacial carrier lifetime, and the energy conversion efficiency was improved. The effective hybridization between the antibody and virus resulted in a linear relationship between the change in photocurrent density and the HEV-LP concentration ranging from 10 fg mL(-1) to 10 ng mL(-1), with a detection limit of 3.5 fg mL(-1). This CdSe-Co(3)O(4)@TiO(2)-based PEC device achieved considerable sensitivity, good specificity, and acceptable stability and demonstrated a significant ability to develop an upgraded device with affordable and portable biosensing capabilities.