Development of a covalent organic framework/graphene oxide aptasensor for electrochemical penicillin detection.

The rapid and sensitive detection of trace antibiotics in environmental and biological samples is crucial for food safety and public health. This study presents a novel electrochemical aptasensor based on a porous covalent organic frameworks/graphene oxide (namely COF/GO) hybrid material for selectively detecting penicillin (PCL). A specific aptamer was immobilized on the modified electrode surface for high-affinity recognition of PCL. The binding event between the aptamer and PCL induces a measurable change in the electrochemical signal, which is quantitatively analyzed using differential pulse voltammetry (DPV). The developed aptasensor demonstrated excellent performance with a wide linear range from 0.01 ng mL- 1 to 10.0 ng mL- 1 and an ultralow detection limit of 2.9 pg mL- 1. The sensor exhibited high selectivity against interfering substances and good stability for storing 8 days. This work highlights the potential of porous COF/GO composite-based electrochemical aptasensors as a powerful tool for real-time monitoring of antibiotic residues in complex matrices.