Semi-derivative voltammetric determination of nitrophenol isomers using a synergistic gold–carbon nanocomposite: resolving the peak overlap
Journal of Electroanalytical Chemistry, vol.1019, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 1019
- Publication Date: 2026
- Doi Number: 10.1016/j.jelechem.2026.120471
- Journal Name: Journal of Electroanalytical Chemistry
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC
- Keywords: Environmental pollutant, Nitrophenol isomers, Semi-derivative voltammetry, Sensor electrode, Simultaneous determination
- Istanbul University Affiliated: No
Abstract
In this study, a highly sensitive electrochemical sensing platform was developed for the selective determination of nitrophenol isomers, which are toxic environmental pollutants of significant concern. A glassy carbon electrode (GC) was modified with multi-walled carbon nanotubes (MWCNTs), polyethyleneimine (PEI), and gold nanoparticles (AuNPs), resulting in a synergistic nanocomposite that provided superior conductivity, enhanced surface area, and strong adsorption capability toward nitrophenols. The electrochemical behavior of 2-nitrophenol (2-NP), 3-nitrophenol (3-NP), and 4-nitrophenol (4-NP) was investigated using linear sweep voltammetry (LSV) coupled with semi-derivative analysis, enabling baseline resolution of their characteristic oxidation peaks at −0.27 V, 0.03 V, and 0.18 V. The remarkable peak separation achieved with this sensor allowed for both individual determination and simultaneous quantification of NP isomers across wide concentration ratios without mutual interference. Crucially, a systematic interference evaluation confirmed the robust selectivity of the platform, especially against structurally similar dihydroxybenzene isomers. Furthermore, excellent linear calibration ranges were established: 10–100 μmol L−1 for 2-NP, 10–200 μmol L−1 for 3-NP, and 2–100 μmol L−1 for 4-NP, and the limit of detection (LOD) values were obtained as 1.5, 0.6, and 0.06 μmol L−1 (S/N = 3) for each isomer, respectively. These results underline the critical role of the nanostructured electrode in promoting adsorption-controlled electrochemical responses and ensuring high analytical precision. Overall, the proposed GC/MWCNTs/PEI/AuNPs sensor, combined with the semi-derivative voltammetry technique, provides a powerful tool for the rapid, selective, and reliable determination of nitrophenol isomers, paving the way for effective monitoring of environmental pollutants in complex real samples. Statistical validation against another voltammetric method using t- and F-tests confirmed the accuracy and reliability of the proposed electrochemical approach.