# An Activated Glassy Carbon Electrode for Rapid, Simple, and Sensitive Voltammetric Analysis of Diclofenac in Tablets

## TL;DR

A new sensor based on an activated glassy carbon electrode is developed for the sensitive and rapid detection of diclofenac in drug tablets.

## Contribution

The novel contribution is the development of a voltammetric procedure using an activated glassy carbon electrode for trace diclofenac analysis.

## Key findings

- The electrode activation process creates functional groups that enhance electron transfer and electrocatalytic activity.
- The developed DPAdSV method achieved detection and quantification limits of 0.25 nM and 0.83 nM, respectively.
- The method was successfully applied to determine diclofenac in commercial pharmaceutical preparations.

## Abstract

This paper proposes an environmentally friendly sensor for determining trace amounts of diclofenac (DCF)—an activated glassy carbon electrode (aGCE). Such a sensor was achieved by simple surface activation of a glassy carbon electrode to perform five cyclic voltammetric scans from −1.5 to 2.5 V at a scan rate (υ) of 100 mV/s in 0.1 M NaOH. This type of activation results in the formation of surface functional groups, which provide several advantages such as the creation of new active sites, the improvement of electron transfer dynamics, and sensor electrocatalytic activity. The electrode prepared in this way was used to develop a new differential pulse adsorptive stripping voltammetric procedure (DPAdSV) for rapid, simple, and sensitive DCF analysis. Thanks to this procedure, the following calibration curve range was obtained: 1–100 nM with low detection and quantification limits of 0.25 and 0.83 nM, respectively. To show the practical application of the method, DCF was successfully determined in commercially available pharmaceutical preparations with the standard addition method.