Department of Nanoengineering, University of California, San Diego, La Jolla, CA 92093-0448, USA.
Analyst. 2017 Mar 13;142(6):918-924. doi: 10.1039/c6an02625g.
A microneedle electrochemical biosensor for the minimally invasive detection of organophosphate (OP) chemical agents is described. The new sensor relies on the coupling of the effective biocatalytic action of organophosphorus hydrolase (OPH) with a hollow-microneedle modified carbon-paste array electrode transducer, and involves rapid square-wave voltammetric (SWV) measurements of the p-nitrophenol product of the OPH enzymatic reaction in the presence of the OP substrate. The scanning-potential SWV transduction mode offers an additional dimension of selectivity compared to common fixed-potential OPH-amperometric biosensors. The microneedle device offers a highly linear response for methyl paraoxon (MPOx) over the range of 20-180 μM, high selectivity in the presence of excess co-existing ascorbic acid and uric acid and a high stability sensor upon exposure to the interstitial fluid (ISF). The OPH microneedle sensor was successfully tested ex vivo using mice skin samples exposed to MPOx, demonstrating its promise for minimally-invasive monitoring of OP agents and pesticides and as a wearable sensor for detecting toxic compounds, in general.
一种用于微创检测有机磷（OP）化学试剂的微针电化学生物传感器被描述。新传感器依赖于有机磷水解酶（OPH）的有效生物催化作用与中空微针修饰的碳糊阵列电极换能器的耦合，并且涉及在存在 OP 底物的情况下快速方波伏安法（SWV）测量 OPH 酶反应的对硝基苯酚产物。与常见的固定电位 OPH 安培生物传感器相比，扫描电位 SWV 转换模式提供了额外的选择性维度。微针装置在 20-180 μM 范围内对甲基对氧磷（MPOx）呈现出高度线性的响应，在存在过量共存抗坏血酸和尿酸的情况下具有高选择性，并且在暴露于间质液（ISF）时传感器具有高稳定性。OPH 微针传感器已成功在暴露于 MPOx 的小鼠皮肤样本上进行了离体测试，表明其有望用于微创监测 OP 试剂和杀虫剂，以及用于检测一般有毒化合物的可穿戴传感器。
