Sensitive and Selective Detection of Chloroform by Current-Voltage Using ZnO Nanorods Modified Electrode; [Pengesanan Sensitif dan Memilih Kloroform oleh Voltan Arus Menggunakan Elektrod Ubah Suai ZnO Nanorod]

• Published in: Sains Malaysiana
• Main Author: Hamid H.A.; Kunakornwattana P.; Isa N.; Razak K.A.
• Format: Article
• Language: English
• Published: Penerbit Universiti Kebangsaan Malaysia 2023
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85163044374&doi=10.17576%2fjsm-2023-5204-11&partnerID=40&md5=719e8c0f010723ab15fc4a10057d5af3

The development of in situ chloroform detection is crucial due to the high risk of carcinogenic effects associated with chloroform exposure. In this study, an electrochemical-based chloroform sensor was fabricated using undoped ZnO nanorods on indium tin oxide (ZnONRs/ITO) electrode to detect chloroform in aqueous-phase samples. Based on the results, the FESEM imaging showed that the ZnONRs exhibited an evenly distributed circular structure with a diameter of 62-90 nm, while the EDX and XRD findings confirmed the presence of Zn and O elements deposited on the electrode surface. Furthermore, the phosphate buffer solution (PBS) solution significantly affected the performance of the modified electrode with an optimal concentration and pH of 0.1 M and pH 7. The results also highlighted the vital function of the modified ZnONRs/ITO electrode as an efficient electron mediator and its catalytic potential to induce chloroform oxidation. Most importantly, the modified ZnONRs/ITO electrode was able to detect the presence of chloroform in real seawater samples, where the repeatability and reproducibility tests achieved a Relative Standard Deviation (RSD) of 1.41% and 2.61%, respectively, indicating the exceptional performance of the modified electrode. Moreover, the modified ZnONRs/ITO electrode recorded a low limit of detection and high sensitivity of 1.50 µM and 2.11 µA/cm2·mM, respectively, within a 0.010-10 mM linear dynamic range. In conclusion, the current-voltage (I-V) method proved the reliable, satisfactory, and effective fabrication of the modified ZnONRs/ITO electrode for chloroform sensing in aqueous-phase samples, including in real seawater samples. © 2023 Penerbit Universiti Kebangsaan Malaysia. All rights reserved.