2D Graphene Sheets as a Sensing Material for the Electroanalysis of Zileuton

Zileuton (ZLT) is an active oral inhibitor of enzyme 5-lipoxygenase, and long-term intake and overdose of ZLT cause adverse effects, leading to critical conditions in patients. This is a well-recognized issue that necessitates a better approach for ZLT sensing. Given the increasing interest in ZLT sensing and the limitations of previous techniques, there is a need for a highly sensitive, robust, and fast operation method that is inexpensive and easy to use. Thus, for the sensitive detection and determination of ZLT, an electrochemical sensor based on graphene was fabricated. Graphene has excellent properties, such as high surface area, low toxicity, conductivity, and electroactive conjugation with biomolecules, making it suitable for sensing. The electrocatalytic property of graphene promotes the redox-coupled reaction of ZLT. Electrochemical investigation of the modifier was carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). An optimization and analysis of the influence of different parameters on the electrochemical behavior of ZLT were carried out using the CV approach. The scan rate study aided in exploring the physicochemical properties of the electrode process, and two electrons with two protons were found to be involved in the electrooxidation of ZLT. The fabricated sensor showed a wide range of linearity with ZLT, from 0.3 µM to 100.0 µM, and the detection limit was evaluated as 0.03 µM under optimized conditions. The analysis of spiked urine samples, with good recovery values for percent RSD, provided support for the efficiency and applicability of the developed electrode.

Ethylcellulose assisted exfoliation of graphite by the ultrasound emulsification: An application in electrochemical acebutolol sensor

This work reports the sonochemical exfoliation of graphite (bath sonication with the frequency of 37/80 kHz and power of 60 W) and its electrocatalytic properties to the β-blocker drug. The pencil graphite (PG) was exfoliated by the ultrasound emulsification with the support of ethyl cellulose (EC). Herein, EC act as an emulsifier which aids to the exfoliation and also stabilizing the exfoliated graphite. This EC assisted PG (ECPG) was characterized by various analytical techniques which showed that ECPG has high crystalline graphene sheets. In some places, EC submerged to the graphene sheets which improve the dispersibility of graphene in water. The performance of ECPG was evaluated to the electrocatalysis of acebutolol (ACE) which exhibited good electrochemical signal. Therefore, the ECPG was utilized to the detection of ACE as the electrochemical sensor electrode. It showed notable sensitivity (2.87 µA μM^-1 cm^-2) appreciable linear range (0.01-200 µM) and satisfactory detection limit (4 nM). Furthermore, it displays acceptable anti-interference properties with other interfering ions.