Nanobiotechnology & Bioanalysis Group, Departament d'Enginyeria Química, Universitat Rovira i Virgili, Avinguda Països Catalans 26, 43007, Tarragona, Spain.
Mikrochim Acta. 2019 Jul 24;186(8):569. doi: 10.1007/s00604-019-3672-6.
Glyphosate [N-(phosphonomethyl)glycine] is the most frequently used herbicide to date. Due to its indiscriminate use, it has become a globally occurring pollutant of surface waters. A biosensor for glyphosate is described here that consists of a carbon nano-onion/tyrosinase conjugate immobilized in a chitosan matrix on a screen-printed electrode. The analytical principle is based on the inhibition of the enzyme tyrosinase by glyphosate. L-DOPA is used as the enzyme substrate. The presence of the carbon nano-onions has a beneficial effect on the sensitivity of the assay. Glyphosate can be amperometrically quantified in the 0.015 to 10 μM concentration range and with a 6.5 nM (1.1 μg L) detection limit. The biosensor is stable more than 2 months at 4 °C. It was applied to the detection of glyphosate in water and soil samples taken from irrigation of a rice field after aerial application. Results were in good agreement with data obtained by a commercial ELISA. Graphical abstract A highly sensitive amperometric biosensor for glyphosate is reported, based on the covalent immobilization of a carbon nano-onion/tyrosinase conjugate on a chitosan matrix.
草甘膦[N-(膦酸甲基)甘氨酸]是迄今为止使用最广泛的除草剂。由于其无差别使用，它已成为一种全球性的地表水污染污染物。本文描述了一种草甘膦生物传感器，它由固定在丝网印刷电极上的壳聚糖基质中的碳纳米洋葱/酪氨酸酶缀合物组成。分析原理基于草甘膦对酶酪氨酸酶的抑制作用。L-多巴被用作酶的底物。碳纳米洋葱的存在对测定的灵敏度有有益的影响。草甘膦可以在 0.015 至 10 μM 的浓度范围内进行电流测定，并具有 6.5 nM（1.1 μg L）的检测限。生物传感器在 4°C 下稳定超过 2 个月。它被应用于检测从稻田空中施用后灌溉的水中和土壤样品中的草甘膦。结果与商业 ELISA 获得的数据吻合良好。
