AuNPs@N-CDs modified pencil graphite electrode as a highly sensitive sensor for the trace determination of ciprofloxacin

A novel electrochemical sensor was developed using pencil graphite electrode modified by N-doped-carbon dots and gold nanoparticles (AuNPs@N-CDs/PGE). The sensor exhibited high sensitivity, stability, and unique features for determination of ciprofloxacin (CIP). Ciprofloxacin is particularly successful in treating urinary tract infections, respiratory illnesses, and gastrointestinal infections caused by susceptible bacteria. Its broad spectrum of antimicrobial activity has made it a vital tool for clinicians combating diverse bacterial pathogens in various organ systems [1,2]. Under optimized conditions, the AuNPs@N-CDs/PGE showed a better electrochemical response compare to bare PGE, N-CDs/PGE, and AuNPs/PGE. Various techniques, including scanning electron microscopy (SEM), X-ray Diffraction (XRD), and energy dispersive X-ray spectroscopy (EDX), FT-IR and VU-visible were employed to analyze the physical and chemical properties of AuNPs@N-CDs/PGE. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized to monitor the electrodeposition process, concentration, and interferents effects. The proposed study revealed a linear concentration range of 5.0×10-10 - 3.0×10-8 M, with a detection limit of 4.3×10-11 M. Additionally, the modified PGE demonstrated successful recoveries in quantitative analysis of CIP in human blood serum, urine and CIP tablet samples, indicating the electrode can be served as an excellent sensitive sensor for the accurate and precise trace measurement of CIP in the real sample. Based on these findings, it can be concluded that the modified electrode stands as a viable option for accurately measuring trace levels of CIP.