Copper molybdenum sulfide (Cu2MoS4) nanoplates as a proficient electrocatalytic interface for enhancing the electrochemical redox signals of ofloxacin for detection in pharmaceutical samples

Abstract

The introduction of nanocatalysts into electrochemical sensing systems has opened up new opportunities in developing advanced electrochemical sensing devices with high sensitivity, selectivity, and stability. In this study, a novel electrochemical sensor for the accurate determination of ofloxacin in a pharmaceutical sample (i.e., in commercial eye drops) was developed using active-site-rich Cu₂MoS₄ nanoplates as an excellent electrocatalytic platform. The electrocatalytic activity of the Cu₂MoS₄ nanoplates was investigated using cyclic voltammetry and sweep linear voltammetry techniques. The results obtained demonstrated that the Cu₂MoS₄ nanoplates exhibit a superior electrocatalytic activity toward the electrochemical oxidation of ofloxacin, thus promoting the sensitive detection of ofloxacin. The ofloxacin oxidation peak current response for Cu₂MoS₄/SPE (screen-printed electrode) was 2.65 times higher than that of the bare SPE. Under optimal conditions, the Cu₂MoS₄ nanoplate-based electrochemical sensor exhibited a linear range from 0.625 to 100 μM with a limit of detection (LOD) of 0.067 μM. Importantly, the proposed sensor showed excellent accuracy in comparison with UPLC-MS/MS analysis (RSD < 3.89%), with good interference immunity, high stability, and repeatability (RSD < 6.3%, n = 20). The obtained results demonstrate the promising applications of transition metal chalcogenide-based electrocatalysts in developing advanced electrochemical sensors.