Novel poly-l-lysine/carboxyl-group enriched graphene oxide/modified electrode preparation, characterization and applications for the electrochemical determination of meloxicam in pharmaceutical tablets and blood serum

Abstract

Electrochemical determination of meloxicam (MLC) was successfully determined at a poly-L-lysine (PLL)/ carboxylated graphene oxide (GO-COOH)/modified glassy carbon electrode (GCE) by cyclic voltammetry (CV) and differential pulse voltammetric (DPV) techniques. The fabricated film characterizations were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The PLL/GO-COOH/GCE was employed for the electrocatalytic oxidation of MLC and the oxidation current of MLC significantly increased when compared to the bare GCE, which clearly shows that the modified electrode shows better electrocatalytic activity than the unmodified GCE. The linear range of the determination of MLC has to be 4 to 104 mM. The low limit of detection (LOD) and sensitivity was found as 0.87 mM and 0.228 mA mM À1 cm À2 . The analytical performance of this proposed sensor has been evaluated in commercially available pharmaceutical tablets and the practicality of the proposed sensor further demonstrated in a real blood serum sample. The obtained results for commercially available tablets were almost equal to the labelled claim of the tablets; from these results it was clearly evident that the proposed electrode shows good catalytic activity towards MLC.

Poly-l-lysine-modified boron-doped diamond electrodes for the amperometric detection of nucleic acid bases

“…The improvement associated with the use of electrochemical method is attributable to the highly positivelycharged PLL that is deposited preferentially by electrostatic interactions [47]. Furthermore, the adsorption process and C-N bonding between PLL and BDD [48,49,59] could also play a role in the deposition of polymerized lysine. Thus, the electrode potential applied during the cyclic voltammetry deposition introduced additional activation energy which enhanced the polymerization process.…”

“…Therefore, we report a simple and convenient one-step method to modify the surface of boron-doped diamond (BDD) by taking advantage of the conducting nature of BDD due to the presence of electropolymerized and chemically polymerized poly-L-lysine (BDD/PLL). The electrostatic interactions between the positively charged -NH 2 groups of PLL and negatively charged GO-COOH stabilize the thin film [48].…”

An eco-friendly fluorometric assay for high-sensitive meloxicam quantitation in biological matrices

“…3C shows the PL intensities of the nano-Cdots at various pH values. The data clearly demonstrate that the PL of the nano-Cdots remains stable and strong within a wide range of pH values (4)(5)(6)(7)(8)(9)(10)(11). However, at pH values lower than 4 or higher than 11, the PL intensities gradually decrease.…”

“…[1][2][3] Although the excellent antiinflammatory effects of Mel for many diseases are known, the high-dose or for extended periods with Mel can cause severe side effects, for instance, gastrointestinal, kidney, and hepatic damage. [4][5][6] In addition, trace amounts of Mel can also pollute natural bodies, causing significant negative impacts on human and aquatic ecosystems. 7,8 Therefore, the development of a simple, reliable, and sensitive method is required to monitor the concentration of Mel in biological samples, which can reduce the risks for optimizing medication dosage and biosphere health based on toxicity limits and medical strategy.…”

“…Nowadays, various common methods, including high-performance liquid chromatography, 9,10 chemiluminescence, 11 capillary electrophoresis, 12 and electrochemical 4,13 methods, are being used to monitor Mel. Although these sensors have been successfully applied for sensitive Mel analysis, most approaches also have many inherent shortcomings, such as complicated sample preparation, the participation of professional technicians, and the need for expensive and sophisticated instruments, which hinder their further utilization in analysis fields.…”