Ruthenium doped Cu-MOF as an efficient sensing platform for the voltammetric detection of ciprofloxacin

Herein, an electrochemical sensing platform based on ruthenium doped copper- metal organic framework (Cu-MOF) was constructed for the sensitive detection of ciprofloxacin antibiotic. A facile room temperature method was used for the synthesis of parent Cu-MOF. The structural features and morphology of the synthesized MOF materials were studied using different characterization techniques like XRD, IR, SEM, XPS etc. The porous structure of MOF combined with higher reaction kinetics due to the incorporation of ruthenium cause a synergistic effect which makes the mixed-valent MOF a promising candidate for sensing studies. The composite, Ru-Cu-TMA (ruthenium doped copper-trimesic acid), prepared was used as an electrode modifier for the sensitive detection of ciprofloxacin by electrochemical technique. Initially, the electrochemical activity of the chemically modified electrodes were examined and Ru-Cu-TMA modified electrode shows the higher current and fast electron transfer which paves the way for its application as sensing material. In addition, more number of active sites formed in MOF by ruthenium doping considerably increases the sensing performance of Ru-Cu-TMA. The electrochemical oxidation of ciprofloxacin on electrode surface is confirmed as an irreversible, diffusion-controlled process. The sensor exhibited a wide linear dynamic range (2.5 – 100 µM) with a lower limit of detection (3.29 nM) and sensitivity 0.0524 µA/µM. Moreover, the sensor demonstrates excellent selectivity, adequate stability, repeatability and can be used for real sample analysis.