Apllication of gold nanoparticles for improvement of analytical characteristics of conductometric enzyme biosensors

In this work, the possibility of application of gold nanoparticles for modification of bioselective elements of conductometric biosensors to improve their analytical characteristics has been tested. A bioselective elements of biosensors based on acetylcholinesterase, butyrylcholinesterase and glucose oxidase have been studied as a model of such system. Immobilization of enzymes on the surface of conductometric transducers was carried out by covalent crosslinking of enzymes by using a crosslinking agent (glutaraldehyde). The conditions for immobilization of acetylcholinesterase with gold nanoparticles in BSA membranes were optimized. The optimal concentration of glutaraldehyde, time of immobilization process, ratio of an amount of enzyme and gold nanoparticles, and the concentration and size of gold nanoparticles were selected. The improved characteristics of the developed biosensors based on enzymes and gold nanoparticles were investigated and compared with the characteristics of biosensors based only on enzymes without nanoparticles addition. It was shown, how the addition of gold nanoparticles to the bioselective element of the biosensor affects the stability of biosensors. In particular, the reproducibility of signals during continuous operation of biosensors, the reproducibility of the manufacture of biosensors and their stability during storage were investigated. Thus, it was shown, that the application of gold nanoparticles in the composition of bioselective elements can improve some characteristics of biosensors, which may be promising for further biosensor application