Evaluation of a photoelectrochemical platform based on strontium titanate, sulfur doped carbon nitride and palladium nanoparticles for detection of SARS-CoV-2 spike glycoprotein S1

This work aims to develop a photoelectrochemical (PEC) platform for detection of SARS-CoV-2 spike glyprotein S1. The PEC platform is based on the modification of a fluorine-doped tin oxide (FTO) coated glass slide with strontium titanate (SrTiO3 or ST), sulfur-doped carbon nitride (g–C3N4–S or CNS) and palladium nanoparticles entrapped in aluminum hydroxide matrix (PdAlO(OH) or PdNPs). The PEC platform was denoted as PdNPs/CNS/ST/FTO and it was characterized by SEM, TEM, FTIR, DRX, and EIS. The PEC response of the PdNPs/CNS/ST/FTO platform was optimized by evaluating the effects of the concentration of the donor molecule, the nature of the buffer, pH, antibody concentration, potential applied to the working electrode, and incubation time. The optimized PdNPs/CNS/ST/FTO PEC platform was modified with 5 μg mL−1 of antibody for determination of SARS-CoV-2 spike glycoprotein S1. A decrease in the photocurrent was observed with an increase in the concentration of SARS-CoV-2 from 1 fg mL−1 to 1000 pg mL−1 showing that the platform is a promising alternative for the detection of S1 protein from SARS-CoV-2. The designed PEC platform exhibited recovery percentages of 96.20% and 109.65% in artificial saliva samples.