A new sensing platform based on poly(valine)-modified carbon paste electrode for the determination of hydroquinone and resorcinol

Abstract

This study offers a simple voltammetric method for quantifying hydroquinone using a poly(valine)-modified carbon paste electrode (PVLMCPE). Differential pulse voltammetry, cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy were utilized to assess the performance of the developed sensor. The oxidation peak current of hydroquinone at the PVLMCPE surface significantly increased in contrast to the bare carbon paste electrode, and overpotentials decreased. Using response surface methodology, a methodical investigation of the electrochemical response of hydroquinone electro-oxidation was carried out, taking potential, pH, polymerization cycle, and scan rate into consideration as important variables. At pH 6.5, phosphate buffer solution produced the best results. In perfect circumstances, the linear detection range showed a high correlation coefficient of 0.920, ranging from 20 to 150 μM. The results showed that the limit of detection and limit of quantification were 0.092 μM and 0.027 μM, respectively. A successful assessment of the results with those obtained using the official method was necessary for validation. Additionally, the created sensor demonstrated a remarkable sensitivity in detecting hydroquinone even in the presence of common interference molecules such as resorcinol. The modified electrode exhibits notable recovery rates and can be used for accurate determination of hydroquinone in real samples due to its broad linear range, high sensitivity, and excellent reproducibility.

Graphical abstract