Ciprofloxacin belongs to second generation of fluoroquinolone antibiotics fluorinated at C6 position with the structure related to nalidixic acid. This broad-spectrum antibiotic is effective through suppressing the synthesis of bacterial DNA [1]. Thanks to its antimicrobial properties, ciprofloxacin is widely used in medicine for treating the infections caused by gram-positive and gram-negative bacteria such as urinary, tissue, digestive and pulmonary infections as well as in veterinary medicine However, extensive consumption may result in allergic reactions and antibiotic resistance [2]. In this sense, the development of fast and reliable analytical methods and coupled protocols for the point-of-care determination of ciprofloxacin in terms of clinical monitoring and pharmaceutical quality control is of high importance.

Herein, electrochemical behavior study and quantification of fluoroquinolone antibiotic ciprofloxacin was performed using boron-doped diamond electrode. Ciprofloxacin provides a diffusion-driven [3] electrode reaction with an irreversible and poorly defined peak at +1.6 V vs. Ag/AgCl electrode in the presence of Britton-Robinson buffer solution pH 4. Linear concentration range from 0.74 to 20.0× 10^-6 mol L^-1, the detection limit of 6.0 ×10^-7 and the relative standard deviation of 2.7% (n = 20, 4.8× 10^-6 mol L^-1 ciprofloxacin) was achieved under optimal differential pulse voltammetric parameters. Effect of possible interfering compounds such as caffeine, penicillin V, amlodipine and folic acid was evaluated with the significant impact on the analyte current response to be observed. Achieved recovery values (88.4% for pharmaceutical, 90.7 and 121.2% for model human urine samples) confirmed satisfactory accuracy of elaborated protocol. The developed approach using point-of-care electrochemical sensor based on boron-doped diamond material could represent inexpensive analytical alternative to separation methods and could be beneficial in analysis of biological samples and in the quality control in pharmaceutical industry. Moreover, the benefits of using BDD electrode as a “green” electrochemical sensor for organic molecules are clearly demonstrated.