Superficially bound acetylcholinesterase based on a chitosan matrix for neurotoxic compound assay by a photographic technique

Abstract

Smartphones scored big success in the last decade and they broke into analytical chemistry as an easy detection system with comparable parameters to standard laboratory equipment. This work focuses on attachment of enzyme acetylcholinesterase (AChE) onto previously activated chitosan. Here, AChE splits alternative substrate indoxyl acetate. Conversion of substrate is blocking or slowing down by inhibitors from which galantamine and tacrine were tested here as model inhibitors with detection limits, 1.1 µM and 0.18 µM, respectively. Measurement procedure was carried out on a 3D three-dimensional printed holder and red-green-blue (RGB) channels served for digital photography evaluation. The method was validated to standard Ellman´s spectrophotometric assay. Long-term stability of immobilized enzyme as well as sensitivity to organic solvents were also tested.