Deep eutectic solvent-mediated synthesis of ZnCo2O4/MWCNT-COOH: Investigation of electrocatalytic activity for gatifloxacin detection

The overuse of gatifloxacin seriously pollutes the environment and cause potential harm to our health. Hence, it is imperative to develop a rapid and sensitive method for gatifloxacin determination. Herein, an efficient electrocatalyst was designed for the voltammetric determination of gatifloxacin based on carboxylated multiwalled carbon nanotubes warped ZnCo2O4 nanoparticles (ZnCo2O4/MWCNT-COOH). The ZnCo2O4 nanoparticles were synthesized by a green deep eutectic solvent-mediated ion-thermal route, and further composited with MWCNTs-COOH. The ZnCo2O4/ MWCNT-COOH combined the catalytic activity of ZnCo2O4 with the high electrical conductivity of MWCNT-COOH, aiming to improve the electrochemical sensing performance toward gatifloxacin. The synergistic interactions between ZnCo2O4 and MWCNT-COOH endowed the ZnCo2O4/MWCNT-COOH with extraordinary catalytic activity for gatifloxacin oxidation. Consequently, the ZnCo2O4/MWCNT-COOH displayed a wide linear response range (0.01 to 10 μM) for detecting gatifloxacin, with a high sensitivity (29.64 μA μM−1 cm−2) and low detection limit (2.0 nM). The ZnCo2O4/MWCNT-COOH showed robust voltammetric responses against potential interfering species, and maintained highly stable responses for at least two weeks. Moreover, the ZnCo2O4/MWCNT-COOH/GCE was successfully used to detect gatifloxacin in water samples with satisfactory recoveries (97.22 − 104.5%). Together with its low cost, environment friendly and rapid response, the ZnCo2O4/MWCNT-COOH shows promising prospects in trace detection of gatifloxacin.