Highly water dispersible poly (caffeic acid - L-arginine)-MoS2 nanocomposite modified sensor for effective electrochemical detection of amlodipine drug

Abstract

The present work applied a facile, green, and versatile approach to preparing self-organized redox polymers on 2D-MoS2 (Molybdenum Disulfide) nanosheets. It was utilized as the modified electrode material for electrochemical determination of 1, 4-dihydropyridine-based antihypertensive drugs viz amlodipine (AMD). Naturally available caffeic acid was used as a precursor, and it was polymerized through a 1, 4-Michael addition reaction with L-arginine. Oxidants and amine functional groups of L-arginine synergistically promote the polymerization of caffeic acid (P (CA-LA)). The P(CA-LA) in the 2D-MoS2 matrix was stabilized via self-assembly by intermolecular interaction between catechol groups and MoS2 sheets. The ultra-sonication process induced the subsequent polymerization and simultaneous exfoliation of MoS2 sheets. The self-assembled P(CA-LA)-MoS2 nanocomposite exhibits a good cyclic voltammetric response with excellent electrochemical oxidation of AMD. The electrochemical response of AMD was explored using a glassy carbon electrode (GCE) modified with P(CA-LA)-MoS2 nanocomposite employing differential pulse voltammetry (DPV). Under the optimized experimental conditions, electrochemical detection of AMD has been performed with a linear correlation between the anodic peak current of AMD observed at 0.8 V. Additionally, the designed self-assembled redox polymer-based nanocomposite sensor exhibited superior selectivity for the detection of AMD with two linear ranges from 0.010 to 16.82 µM and 16.82 to 433.3 µM with good detection limits of 3.6 nM. Moreover, the synergic interactions of polymers and MoS2 and their self-assembly nature can offer a good sensitivity of 0.42 μA μM−1 cm−2. Hence, the electrochemical behavior of self-assembled P(CA-LA)-MoS2/GCE may provide new insights into the recent era of electrodes and sensors.