Separation Science Institute, The Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, 710049, China.
Separation Science Institute, The Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, 710049, China.
Talanta. 2019 Sep 1;202:384-391. doi: 10.1016/j.talanta.2019.05.031. Epub 2019 May 6.
A novel microfluidic paper-based analytical device (μPAD) was developed with benzoquinone (BQ)-mediated E. coli respiration method to measure the biotoxicities of pollutants. Functional units including sample injection, fluid-cell separation, all-carbon electrode-enabled electrochemical detection, were integrated on a piece of chromatography paper. The three-electrode, working electrode, counter electrode and reference electrode, were simultaneously screen-printed on the μPAD with conductive carbon ink. The satisfying electrochemical performance of the paper-based carbon three-electrode was confirmed by cyclic voltammetry detecting K [Fe(CN)]. The process of cell toxication was considered that toxicants inhibited cell respiration and diminished the electrons on E. coli respiratory chain. It was quantitatively reflected by measuring oxidation current of hydroquinone (HQ) as a reduced state of the redox mediator BQ after the incubation of cells with pollutants. The current detection time, BQ concentration and E. coli incubation time were carefully optimized to establish the systematic optimized operations of BQ-mediated E. coli respiration method. Using the fabricated μPAD the half inhibitory concentration (IC) were Cu solution 13.5 μg mL, Cu-soil 21.4 mg kg, penicillin sodium-soil 85.1 mg kg, and IC of Pb solution was 60.0 μg mL. Detection of pesticide residues in vegetable juices were accomplished in a similar way. The proposed method is fascinating on three points; 1) The generality in the biotoxicity detection depends on toxicants inducing cellular respiratory inhibition; 2) The portability and affordability make it convenient for practical applications, because of replacing incubators and centrifuges; 3) There is potential applicability in less-developed areas due to its simple operation and low-cost.
开发了一种新型的微流控纸基分析装置（μPAD），采用苯醌（BQ）介导的大肠杆菌呼吸法来测量污染物的生物毒性。包括样品注入、液池分离、全碳电极电化学检测在内的功能单元集成在一张色谱纸上。工作电极、对电极和参比电极这三个电极通过导电碳墨同时被丝网印刷在 μPAD 上。通过循环伏安法检测 K [Fe(CN) 来确认纸基碳三电极的电化学性能令人满意。细胞中毒过程被认为是有毒物质抑制细胞呼吸并减少大肠杆菌呼吸链上的电子。通过测量与污染物孵育后细胞还原态 BQ 的氧化电流来定量反映这一过程。仔细优化了电流检测时间、BQ 浓度和大肠杆菌孵育时间，以建立 BQ 介导的大肠杆菌呼吸法的系统优化操作。使用所制造的 μPAD，Cu 溶液的半抑制浓度（IC）为 13.5μg/mL，Cu-土壤为 21.4mg/kg，青霉素钠-土壤为 85.1mg/kg，Pb 溶液的 IC 为 60.0μg/mL。采用类似的方法检测蔬菜汁中的农药残留。该方法具有三个特点：1）生物毒性检测的通用性取决于有毒物质诱导细胞呼吸抑制的能力；2）便携性和经济性使其非常适合实际应用，因为它可以替代培养箱和离心机；3）由于其操作简单、成本低廉，在欠发达地区具有潜在的适用性。
