He Yi, Zhu Jin, Li Libo, You Tianyan, Chen Xuegeng
Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang 212013, China
College of Agricultural Equipment Engineering, Henan University of Science and Technology, Luoyang 471003, China.
Biosensors (Basel). 2025 Jul 5;15(7):433. doi: 10.3390/bios15070433.
Diuron (DU) is a widely used phenylurea herbicide designed to inhibit weed growth, but its high toxicity and prolonged half-life contribute significantly to environmental contamination. The majority of electrochemical (EC) sensors typically rely on a single response signal for the detection of DU, rendering them highly susceptible to interference from variable background noise in complex environments, thereby reducing the selectivity and robustness. By integrating molecularly imprinted polymer (MIP) with a ratiometric strategy, the aforementioned issues could be solved. In this study, a novel signal on-off ratiometric MIP-EC sensor was developed based on the MXene/PEI-MWCNTs nanocomposite for the detection of DU. Positively charged PEI-MWCNTs was used as an interlayer spacer and embedded into negatively charged MXene by a simple electrostatic self-assembly method. This effectively prevented the agglomeration of MXene and enhanced its electrocatalytic performance. The MIP was synthesized via electropolymerization with DU serving as the template molecule and the selectivity was enhanced by leveraging the gate effect of MIP. Subsequently, a ratiometric MIP-EC sensor was designed by introducing [Fe(CN)] into the electrolyte solution as an internal reference. Additionally, the current ratio signal (I/I) and DU concentration exhibited a good linear relationship within the range of 0.1 to 100 µM, with a limit of detection (LOD) of 30 nM (S/N = 3). In comparison with conventional single-signal MIP-EC sensing, the developed ratiometric MIP-EC sensing demonstrates superior reproducibility and accuracy. At the same time, the proposed sensor was successfully applied to the quantitative analysis of DU residues in soil samples, yielding highly satisfactory results.
敌草隆（DU）是一种广泛使用的苯基脲类除草剂，旨在抑制杂草生长，但其高毒性和较长的半衰期对环境污染有显著影响。大多数电化学（EC）传感器通常依靠单一响应信号来检测DU，这使得它们极易受到复杂环境中可变背景噪声的干扰，从而降低了选择性和稳定性。通过将分子印迹聚合物（MIP）与比率测定策略相结合，可以解决上述问题。在本研究中，基于MXene/PEI-MWCNTs纳米复合材料开发了一种新型的信号开关比率型MIP-EC传感器用于检测DU。带正电荷的PEI-MWCNTs用作中间间隔层，并通过简单的静电自组装方法嵌入带负电荷的MXene中。这有效地防止了MXene的团聚并增强了其电催化性能。以DU为模板分子通过电聚合合成MIP，并利用MIP的门控效应提高选择性。随后，通过将[Fe(CN)]引入电解液作为内参设计了一种比率型MIP-EC传感器。此外，电流比率信号（I/I）与DU浓度在0.1至100 µM范围内呈现良好的线性关系，检测限（LOD）为30 nM（S/N = 3）。与传统的单信号MIP-EC传感相比，所开发的比率型MIP-EC传感具有更高的重现性和准确性。同时，所提出的传感器成功应用于土壤样品中DU残留的定量分析，结果非常令人满意。
