Architecting of an aptasensor for the staphylococcus aureus analysis by modification of the screen-printed carbon electrode with aptamer/Ag–Cs-Gr QDs/NTiO2

Given the many issues bacterial infections cause to humans and the necessity for their detection, in this work we developed a robust aptasensor for prompt, ultrasensitive, and selective analysis of staphylococcus aureus bacterium (S. aureus). A nanocomposite of Ag nanoparticles, chitosan, graphene quantum dots, and nitrogen-doped TiO2 nanoparticles (Ag–Cs-Gr QDs/NTiO2) was synthesized, and thoroughly characterized by XRD, FT-IR, and FE-SEM spectroscopic methods. The surface of screen-printed carbon electrodes modified with Ag–Cs-Gr QDs/NTiO2 nanocomposite was utilized as a compatible platform for aptamer attachment. The aptasensor accurately determined S. aureus in the dynamic range of 10–5 × 108 CFU/mL with detection limit of 3.3 CFU/mL. The monitoring of the practical performance of aptasensor in human serum samples revealed its superiority over the conventional methods (relative recovery of 96.25–103.33%). The Ag–Cs-Gr QDs/NTiO2-based aptasensor offers facile, biocompatibility, good repeatability, reproducibility (RSD = 3.66%), label free and stabile strategy for sensitive S. aureus analysis free from biomolecules interferences in actual specimens. [Display omitted] •A sensitive electrochemical aptasensor was developed for S. aureus analysis.•The Cs-Gr QDs/NTiO2 platform was prepared for aptasensor construction.•High reproducible analysis of S. aureus was done by Apt-Ag-Cs-Gr QDs-NTiO2/SPCE.•The Apt/Ag–Cs-Gr QDs/NTiO2/SPCE successfully determined S. aureus in a real sample.