Accumulation and exposure of organophosphate pesticides are of great concern today owing to their abundant usage and potential health hazards. Harmful effects of organophosphate pesticide exposure and limitations of the available treatment methods necessitate the development of reliable, selective, cost-effective, and sensitive methods of detection. We developed a novel biosensor based on the enzymatic action of recombinant organophosphorus hydrolase (OPH) expressed in E. coli. We report the development of colorimetric biosensors made of His-Nus-OPH as well as His-Nus-OPH loaded alginate microspheres. The colorimetric detection method developed using solution-phase and alginate-encapsulated His-Nus-OPH exhibited detection limits of 0.045 and 0.039 mM, respectively, for ethyl paraoxon, and 0.101 and 0.049 mM, respectively, for methyl parathion. Additionally, fluorescence measurement using pH-sensitive fluorescein isothiocyanate (FITC) was used to sense the quantity of organophosphorus pesticides. The fluorometric detection method using solution-phase His-Nus-OPH, with ethyl paraoxon and methyl parathion as the substrate, reveals the lower limit of detection as 0.014 mM and 0.044 mM, respectively. Our results demonstrate the viability of His-Nus-OPH for OP detection with good sensitivity, LOD, and linear range. We report the first use of N-terminal His-NusA-tagged OPH, which enhances solubility significantly and presents a significant advance for the scientific community.

由于有机磷农药的大量使用和潜在的健康危害，今天人们对有机磷农药的积累和暴露非常关注。有机磷农药暴露的有害影响和现有处理方法的局限性需要开发可靠、选择性、成本效益高和灵敏的检测方法。我们开发了一种基于在大肠杆菌中表达的重组有机磷水解酶 (OPH) 的酶促作用的新型生物传感器. 我们报告了由 His-Nus-OPH 以及载有 His-Nus-OPH 的藻酸盐微球制成的比色生物传感器的发展。使用溶液相和海藻酸盐封装的 His-Nus-OPH 开发的比色检测方法对乙基对氧磷的检测限分别为 0.045 和 0.039 mM，对甲基对硫磷的检测限分别为 0.101 和 0.049 mM。此外，使用对 pH 敏感的异硫氰酸荧光素 (FITC) 进行的荧光测量可用于检测有机磷农药的数量。使用液相His-Nus-OPH的荧光检测方法，以乙基对氧磷和甲基对硫磷为底物，检测下限分别为0.014 mM和0.044 mM。我们的结果证明了 His-Nus-OPH 用于 OP 检测的可行性，具有良好的灵敏度、LOD 和线性范围。N-末端 His-NusA 标记的 OPH，显着提高了溶解度，并为科学界带来了重大进展。