Influence of the Aminated Conditions on the pH Sensitivity of Silica and Amorphous Silicon Film

International audienceSilicon nitride has been widely used as a pH sensitive membrane of the ion sensitive field e#ect transistor (ISFET) thanks to the high reactivity of the SiNH2 sites to the H f ions. In this paper, we report experimental results on the H+ sensitivity of silica and amorphous silicon aminated films, obtained by the photo-CVD. We have studied the dependence of their response to pH as a function of the time and the temperature of amination of thejIm. The response of the aminatedjilms (silica and amorphous silicon) is quasi-Nernstian for amination exposure time higher than 1 min, deposited at temperature lower than 200°C. A theoretical model of deposition is presented. It can explain the influence of the deposition conditions. Published by Elsevier Science Limited

Amperometric Polyphenol Biosensor Based on Tyrosinase Immobilization on CoAl Layered Double Hydroxide Thins Films

International audienceAn amperometric biosensor based on tyrosinase immobilized on the sensor surface has been used for the detection of polyphenols extracted from green tea. The immobilization was ensured by the crosslinking method on thins films of CoAlSO 4 layered double hydroxide recovering screen-printed gold electrodes. Electrochemical measurements show that this biosensor is able to detect tea polyphenols by following the reduction of compounds enzymatically generated. Its response is linear in the concentration range of [0-2,4 µM] with high sensitivity and stability, since it retains 90% of its original response after 20 days