Innovative aptasensor design for chlorpyrifos detection: Combining carbon nanofibers, doped carbon dots, and gold nanoparticles

Chlorpyrifos (CPF) is an organophosphate pesticide that is essential for controlling agricultural pests. Nevertheless, residues of this compound, even at low concentrations, raise substantial concerns regarding the environment and human health, including neurotoxic, genotoxic, and reproductive effects. This study aimed to design and fabricate a highly sensitive aptamer-based electrochemical biosensor utilizing P@N, S-CDs/CNFs with gold nanoparticles (AuNPs) for the detection of CPF in fruit and vegetable samples. Initially, nitrogen- and sulfur-co-doped carbon dots (N, S-CDs) were incorporated into polyacrylonitrile (PAN) polymer, resulting in the formation of N, S-CDs/CNFs via electrospinning. Subsequently, P@N, S-CDs/CNFs were produced during the heat treatment process. The hybrid material (P@N, S-CDs/CNFs) was used to modify the surface of the glassy carbon electrode (GCE), followed by the placement of AuNPs on the GCE modified with P@N, S-CDs/CNFs using the drop casting method. The successful synthesis of the nanomaterials was confirmed through XRD, FTIR, and SEM analyses. Under optimal conditions, the aptasensor demonstrated an extensive linear range from 0.1 fg mL −1 to 800 pg mL −1 , with a calculated limit of detection as low as 0.033 fg mL −1 . The capability of the aptasensor to detect CPF in real samples was assessed by testing extracts of cucumber, tomato, and lettuce.