Flat-chip microanalytical enzyme sensor for salivary amylase activity

The purpose of our research is to demonstrate a new design of a flat-chip microanalytical enzyme sensor (flat-chip sensor) for salivary amylase activity, which may be used for wearable analytical systems. A flat-chip sensor was fabricated using a flow cell, which was about the same size as a C battery (16.9 ml). In order to miniaturize the flow cell, two enzymatic membranes containing maltose phosphorylase and glucose oxidase were immobilised on it. Regarding the fabricated flat-chip sensor, the optimum conditions of three parameters, immobilising method of the enzymatic membrane, dropping volume of the mixed enzymatic solution and flow rate of the sample solution were examined. As a result, an analytical system for 0-190 kU/l of amylase activity was fabricated with a sample volume of 50 μJ and a flow cell volume of 16.9 ml.