Fibre-optic pesticide biosensor based on covalently immobilized acetylcholinesterase and thymol blue

Substituent effects on absorption spectra of pH indicators: An experimental and computational study of sulfonphthaleine dyes

“…[42][43][44][45][46][47][48][49][50][51][52][53] Sulfonphtaleine dyes are not only sensitive to pH, but are also used in sensor applictions for detecting pesticides, CO 2 and ammonia. [54][55][56] The development of new glassy carbon electrodes also deserves mention. [57][58][59][60] Other interesting studies include the hyperpolarizabilities of these dyes and also the possibility to serve as starting point for the development of new dyes.…”

Modified Cholinesterase Technology in the Construction of Biosensors for Organophosphorus Nerve Agents and Pesticides Detection

“…It is present in the evanescent zone of the fiber surface and is quenched by produced protons, which enables detecting the enzyme activity. Totally different is the fiber optic biosensor based on covalently bonded AChE on isothiocyanate glass mixed with thymol blue (immobilized on aminopropylic glass) and subsequently measuring the reflectance of color changes of a pH-sensitive indicator in the course of enzyme-catalyzed hydrolysis at 600 nm (Andres & Narayanaswamy, 1997). Fiber-optic biosensors provide a lot of benefits such as the possibility of miniaturization, the possibility of remote sensing, in situ monitoring without the necessity of direct electric supply, and except for that they minimize undesirable interactions between the fluorescent detector and the sample.…”

The Potential of Flow-Based Optosensing Devices for Pesticide Assessment

“…In these systems, the pH change generated by the release of acetic acid during the enzymatic reaction between acetyl choline and AChE is measured. The monitoring of the pH change can be carried out by using a colorimetric or fluorimetric indicator such as fluorescein isothiocyanate (FITC) (Rogers et al, 1991), thymol blue (Andres & Narayanaswamy, 1997) or chlorophenol red (Xavier et al, 2000).…”