Bhandari Sanjeev, Sen Bhaskar, Khatua Snehadrinarayan, Singh L Robindro, Parihar Vijay Singh, Mahato Mrityunjoy
Physics Division, Department of Basic Sciences and Social Sciences, School of Technology, North-Eastern Hill University Shillong Meghalaya 793022 India
Centre for Advanced Studies, Department of Chemistry, North-Eastern Hill University Shillong Meghalaya 793022 India.
RSC Adv. 2024 Sep 18;14(40):29542-29558. doi: 10.1039/d4ra04188g. eCollection 2024 Sep 12.
Bifenthrin (BF), a widely used pyrethroid pesticide in farming, lacks highly sensitive and selective sensors despite its extensive application. Ruthenium complexes are very effective for selective sensing applications but suffer from structural instability at elevated conditions, electrochemical activity, and the use of costly electrolytes. This work improves their electrochemical activity and mechanical strength by incorporating silver nanowires and replacing the costly electrolyte with abundant KCl + PBS, resulting in enhanced signal performance. Herein, a ruthenium complex containing composite film was immobilized on a platinum (Pt) electrode using Langmuir Blodgett technique. The fabricated sensor has been characterized by differential pulse voltammetry (DPV) based electrochemical technique. The BF pesticide sensing parameters, including the limit of detection (LOD), linear range (LR), and sensitivity, were evaluated using SWV, DPV, and CV techniques. Among these, the DPV technique demonstrated the best performance, achieving a sensitivity of 0.648 μA cm μM, a LR of 1-10 μM, and a LOD of 1 μM. The relative standard deviation (RSD) values using DPV are found to be 6.3% (repeatability study), 3% (reproducibility study), 8% (metal ion interference), 5% (organic species interference), and 2% (real sample study), which are much lesser than the World Health Organization (WHO) recommendation of RSD value on the pesticide ( 20%). The BF sensor demonstrated a selectivity of 2× difference of peak height response compared to similar pesticides. The reported pesticide sensor will open new options for sensor research using metal complex-based LB film nanocomposite.
联苯菊酯（BF）是一种在农业中广泛使用的拟除虫菊酯类农药，尽管其应用广泛，但缺乏高灵敏度和选择性的传感器。钌配合物在选择性传感应用中非常有效，但在高温条件下存在结构不稳定、电化学活性以及使用昂贵电解质等问题。这项工作通过掺入银纳米线并用丰富的KCl + PBS替代昂贵的电解质来提高其电化学活性和机械强度，从而增强信号性能。在此，使用朗缪尔-布洛杰特技术将含钌配合物的复合膜固定在铂（Pt）电极上。所制备的传感器已通过基于差分脉冲伏安法（DPV）的电化学技术进行了表征。使用方波伏安法（SWV）、差分脉冲伏安法（DPV）和循环伏安法（CV）技术评估了BF农药的传感参数，包括检测限（LOD）、线性范围（LR）和灵敏度。其中，DPV技术表现出最佳性能，灵敏度为0.648 μA cm μM，线性范围为1 - 10 μM，检测限为1 μM。发现使用DPV的相对标准偏差（RSD）值分别为6.3%（重复性研究）、3%（再现性研究）、8%（金属离子干扰）、5%（有机物种干扰）和2%（实际样品研究），远低于世界卫生组织（WHO）对农药RSD值的建议（20%）。BF传感器与类似农药相比，峰高响应差异的选择性为2倍。所报道的农药传感器将为使用基于金属配合物的LB膜纳米复合材料的传感器研究开辟新的选择。
