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有机磷属于神经毒物,能够抑制血液和组织中乙酰胆碱酯酶(ACh E)的活性。水溶液中的氯化硫代乙酰胆碱(ATCl)在ACh E催化下水解形成巯基胆碱(TCl),TCl在电极表面氧化,可以检测到较大的电流信号。有机磷的存在,降低ACh E活性的同时,使得催化水解产生的TCl电化学信号减小。鉴于此原理,研究构建了碳纳米管/聚4-(2,5-二噻吩-1-吡咯)苯胺/乙酰胆碱酯酶电化学传感器(ACh E/p-DSPAB/FMWNTs),对溶液的有机磷进行定量分析。电极MWNTs修饰量为1.0μg/cm2,电极ACh E固载量为1.5U。最佳条件下,以3.0 ng/m L氯化硫代乙胆碱(ATCl)为底物,在5.0 m L 50 mmol/L PBS(p H=7.0)溶液中,采用微分脉冲伏安法进行测定,电位增量0.006 V、脉冲幅度0.05 V、脉冲宽度0.1 V、脉冲间隔0.1 s。传感器对有机磷检测线性范围为3.00 ng/m L~90.00ng/m L,最低检测限为1.00 ng/m L(S/N=3)。与高效液相色谱法相比,该法具有简便、准确、快速、样品预处理简单等优点。
Organophosphorus is a neurotoxic agent that inhibits acetylcholinesterase (AChE) activity in blood and tissues. Thiochlorothiocholine (ATCl) in aqueous solution is hydrolyzed to form thiol choline (TCl) catalyzed by ACh E, and the oxidation of TCl on the surface of the electrode can detect a large current signal. The presence of organophosphorus reduces ACh E activity and at the same time reduces the electrochemical signal of TCl produced by catalytic hydrolysis. In view of this principle, the electrochemical sensor (ACh E / p-DSPAB / FMWNTs) of carbon nanotubes / poly 4- (2,5-dithiophene-1-pyrrole) aniline / Quantitative analysis. Electrode MWNTs modified amount of 1.0μg / cm2, electrode ACh E solid load of 1.5U. Under optimal conditions, differential pulse voltammetry was carried out in 5.0 m L of 50 mmol / L PBS (p H = 7.0) with 3.0 ng / mL of ATCC as substrate Measurement, potential increment 0.006 V, pulse amplitude 0.05 V, pulse width 0.1 V, pulse interval 0.1 s. The linear range of the sensor for organophosphate detection ranged from 3.00 ng / m L to 90.00 ng / m L with a minimum detection limit of 1.00 ng / m L (S / N = 3). Compared with HPLC, this method is simple, accurate, rapid, sample pretreatment is simple and so on.