Neufeld T, Eshkenazi I, Cohen E, Rishpon J
Department of Molecular Microbiology and Biotechnology, Tel-Aviv University, Israel.
Biosens Bioelectron. 2000 Aug;15(5-6):323-9. doi: 10.1016/s0956-5663(00)00073-7.
We describe a disposable, amperometric micro flow injection electrochemical biosensor that can be applied to the identification and quantification of highly toxic organophosphorus (OP) compounds in the environment, on the spot and in a short time. The system traces very small quantities of OP by monitoring the enzymatic reaction of acetylcholine esterase (AChE) and its inhibition. The sensor is sensitive, rapid, small, inexpensive, disposable and can be operated by non-professional technicians. The electrochemical cell consists of screen-printed electrodes covered with an enzymatic membrane and placed in a home-made flow cell. The electrodes are connected to a computer-controlled potentiostat. We quantitatively detected the OP compound, dimethyl 2,2-dichlorovinyl phosphate (DDVP), by monitoring the OP induced decrease in enzymatic degradation of the substrate, acetylthiocholine chloride (ATCh), to thiocholine and acetic acid. Thiocholine reacts with hexacyanoferrate ion in the working solution and the reduction of Fe(CN)6 to Fe(CN)6 and its subsequent reoxidization by the electrode generates very sharp, rapid and reproducible electric signals. The ability to detect low quantities is extremely important when dealing with hazardous environmental pollutants.
我们描述了一种一次性安培微流注射电化学生物传感器，它可用于现场快速鉴定和定量环境中剧毒有机磷（OP）化合物。该系统通过监测乙酰胆碱酯酶（AChE）的酶促反应及其抑制作用来追踪极少量的OP。该传感器灵敏、快速、体积小、成本低、一次性使用，且非专业技术人员即可操作。电化学生电池由覆盖有酶膜的丝网印刷电极组成，并置于自制的流通池中。电极连接到计算机控制的恒电位仪上。我们通过监测OP引起的底物氯化乙酰硫代胆碱（ATCh）向硫代胆碱和乙酸的酶促降解减少，定量检测了OP化合物2,2-二氯乙烯基磷酸二甲酯（DDVP）。硫代胆碱与工作溶液中的六氰合铁离子反应，Fe(CN)6还原为Fe(CN)6，随后被电极再氧化，产生非常尖锐、快速且可重复的电信号。在处理有害环境污染物时，检测低含量的能力极为重要。
