Jahandideh-Roudsari Seyedeh Reyhaneh, Shourian Mostafa, Homaei Ahmad
Department of Marine Biology, Faculty of Marine Science and Technology, University of Hormozgan, P.O. Box 3995, Bandar Abbas, Iran.
Department of Biology, Faculty of Sciences, University of Guilan, Rasht, Iran.
Bioprocess Biosyst Eng. 2025 Jul 13. doi: 10.1007/s00449-025-03206-5.
CoO/rGO nanoparticles were used to modify a glassy carbon electrode (GCE), where reduced graphene oxide (rGO) serves as an intermediate between graphene and graphene oxide, featuring a carbon framework enriched with oxygen-containing hydrophilic functional groups. The structural and morphological characterization of the modified electrode was carried out using Raman spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS). Electrochemical performance was evaluated through cyclic voltammetry (CV) and chronoamperometry, revealing effective electron transfer between the nanoparticles and immobilized choline oxidase (ChOx). The apparent heterogeneous electron transfer rate constants (K) were calculated as 0.99 s for CoO/rGO and 5.89 s for ChOx/CoO/rGO. The biosensor demonstrated excellent analytical performance for choline detection, with a linear response range of 5-60 µM, a sensitivity of 0.0216 µA µM, and a detection limit of 0.811 µM. Notably, the developed biosensor also exhibited a strong electrochemical response to the organophosphorus pesticide diazinon, indicating its potential for environmental monitoring. Given that diazinon is a widely used organophosphorus pesticide with high toxicity to humans and the environment, its sensitive detection is critical for monitoring and controlling pesticide contamination.
氧化钴/还原氧化石墨烯纳米颗粒用于修饰玻碳电极（GCE），其中还原氧化石墨烯（rGO）作为石墨烯和氧化石墨烯之间的中间体，具有富含含氧亲水性官能团的碳骨架。使用拉曼光谱、X射线衍射（XRD）以及扫描电子显微镜与能量色散光谱联用（SEM-EDS）对修饰电极进行结构和形态表征。通过循环伏安法（CV）和计时电流法评估电化学性能，结果表明纳米颗粒与固定化胆碱氧化酶（ChOx）之间存在有效的电子转移。计算得到氧化钴/还原氧化石墨烯的表观异相电子转移速率常数（K）为0.99 s，胆碱氧化酶/氧化钴/还原氧化石墨烯的为5.89 s。该生物传感器在胆碱检测方面表现出优异的分析性能，线性响应范围为5 - 60 µM，灵敏度为0.0216 µA µM，检测限为0.811 µM。值得注意的是，所开发的生物传感器对有机磷农药二嗪农也表现出强烈的电化学响应，表明其在环境监测方面的潜力。鉴于二嗪农是一种广泛使用的有机磷农药，对人类和环境具有高毒性，其灵敏检测对于监测和控制农药污染至关重要。
