Modified Biosensor for Cholinesterase Inhibitors with Guinea Green B as the Color Indicator

Abstract

Colorimetric biosensors of cholinesterase inhibitors are ideal for fast, reliable, and very simple detection of agents in air, in water, and on surfaces. This paper describes an innovation of the Czech Detehit biosensor, which is based on a biochemical enzymatic reaction visualized by using Ellman’s reagent as a chromogenic indicator. The modification basically consists of a much more distinct color response of the biosensor, attained through optimization of the reaction system by using Guinea Green B as the indicator. The performance of the modified biosensor was verified on the chemical warfare agents (sarin, soman, cyclosarin, and VX) in water. The detection limits ascertained visually (with the naked eye) were about 0.001 µg/mL in water (exposure time 60 s, inhibition efficiency 25%).

Paper-Based Analytical Device for the On-Site Detection of Nerve Agents

“…A comparison of our device with other reported paper devices for pesticide and nerve agent testing and with DETEHIT is shown in Table S1. ,− Given the cumbersome procedure, long incubation time, and low robustness of the other devices and the selectivity to nerve agents, the present device is believed to be useful for rapid testing of unknown materials at the scene of a terrorist attack. The good selectivity of the present device is due in part to the short incubation time, which allows for rapid detection.…”

“…11 These approaches have achieved acceptable separation, identification, and limit of detection (LOD) by integrating pretreatment procedures; however, they have several disadvantages, including complex channel design and fabrication; high-voltage manipulation using costly instruments; 12 variable response to organic solvents, temperature, pH, and storage; as well as dangerous or troublesome stepwise operation. 13 Microfluidic paper-based analytical devices (μPADs) have been used for point-of-care testing and on-site detection in various analytical fields, including clinical diagnosis and tests for toxins in the context of food and environmental analysis, because a paper substrate has several advantages as an analytical tool. 14−22 These advantages are as follows: (1) cellulose-based paper is easily available and cheap; (2) the fibrous cellulose structure can apply capillary force without an external power source and wick liquids; (3) hydrophobic zones can be formed by typical cutting or printing methods; (4) paper is portable and disposable; and (5) various detection methods can be selected in accordance with each need.…”

“…Recent research and development of “lab-on-a-chip” technologies have led to the development of on-site devices for the detection of organophosphorus compounds in aqueous solutions, , in particular, electrochemical microchips and colorimetric biosensors . These approaches have achieved acceptable separation, identification, and limit of detection (LOD) by integrating pretreatment procedures; however, they have several disadvantages, including complex channel design and fabrication; high-voltage manipulation using costly instruments; variable response to organic solvents, temperature, pH, and storage; as well as dangerous or troublesome stepwise operation …”

Enzyme-Based Electrochemical Biosensors for Microfluidic Platforms to Detect Pharmaceutical Residues in Wastewater

“…Oxidase/Peroxidase based-biosensors have been successfully used to detect molecules such as glucose, alcohol, putrescine, oxygen, hydrogen peroxide and other small metabolites. This has been useful for applications in the food industry, medical diagnosis and in vitro assays of pharmaceutical trials [21,59,63,64,65]. Even though these enzymatic biosensors exhibit high sensitivity and selectivity toward the detection of small molecules, their use is limited due to issues regarding low stability of the enzyme molecules during the fabrication, special storage conditions, and complicated implementation protocols [63].…”

A Strip Biosensor with Guinea Green B and Fuchsin Basic Color Indicators on a Glass Nanofiber Carrier for the Cholinesterase Detection of Nerve Agents

“…17 The authors also proposed a modified biosensor with a 2,6-dichlorophenolindophenol indicator with a blue–white color transition 18 and a biosensor with a Guinea green B indicator with a green–white transition. 13…”