A Ratiometric Electrochemical Sensor for Antiepileptic Drug of Carbamazepine Based on Electroactive Ni2+-Terephthalic Acid Mof

Abstract

Carbamazepine (CBZ), an anticonvulsant and mood stabilizer used extensively for epilepsy, requires a reliable and sensitive monitoring assay for assessing and optimizing the dosage administered to epileptic patients. In this work, spherical nickel-based metal-organic framework materials (Ni-MOFs) consisting of nanosheets were synthesized and cast on glassy carbon electrode (GCE) to prepare a novel ratiometric CBZ electrochemical sensor. The electrochemical test results showed that the Ni-MOF-based sensor had a pair of reversible redox peaks at +0.54 V and +0.39 V, respectively, originating from the Ni3+/Ni2+ pair. Meanwhile, CBZ presented an intense irreversible oxidation peak at +1.22 V on the sensor, and its peak current intensity was significantly higher than that on bare GCE and Nafion/GCE, indicating significant electrocatalysis of Ni-MOF on the CBZ. Further, ratiometric sensing detection of CBZ can be achieved by measuring the ratio (R) of oxidation peak currents between CBZ and Ni-MOF, using the Ni-MOF’s oxidation peak as the internal reference signal. Under the optimal experimental conditions, the sensor can detect CBZ in the concentration range of from 20 to 300 µM with the detection limit as low as 1.03 µM. The recoveries of 93.00 - 104.3% were obtained when the sensor was used for the determination of CBZ in serum samples, which demonstrated that the sensor has potential applications in the monitoring of CBZ residues in biological samples.

Keywords: electrochemical sensor, Ratiometric, Carbamazepine, Ni-MOF, Serum