Start
Jul 17, 2014 - 17:00
End
Jul 17, 2014 - 18:00
Venue
Room 118 Creativity Hall Chemical Engineering
Event Type
Speaker
Anees Khan Phd Student IITB
Title
Mesoporous silica as a host for impregnation of enzyme and metal nanoparticles for improved sensor performance
Abstract Immobilized enzyme based glucose biosensors are in demand for diabetes management. In the present work glucose oxidase (GOD) enzyme was immobilized in mesoporous silica (SBA-15) host particles. The effect of external morphology aspect ratio internal pore diameter of SBA-15 particles and surface functionalization of SBA-15 on GOD activity and performance of the glucose biosensor was studied. Activity and glucose sensing experiments suggest that amine functionalized SBA-15 host particles (cuboid morphology) with smaller aspect ratio (1.1) and larger mesopore diameter (11.4 nm) together with appropriate enzyme loading density (0.043 μg GOD/cm2 area of electrode) and ferrocene (an electron mediator 40 μM) ensures good sensor performance. This led to a large linear range of glucose (0.4-13.0 mM) better sensitivity (0.65 µAcm-2mM-1) and a short response time (< 5 s). As the glucose sensing in this work was based on enzymatically generated hydrogen peroxide (H2O2) hence a highly selective and sensitive H2O2 chemical sensor was developed by impregnating silver nanoparticles (AgNPs) in amine functionalized cuboid SBA-15 host particles. The sensor showed a wide linearity range (5.3-124.5 mM H2O2) and a high sensitivity of 171.3 μA cm−2 mM−1 due to a high loading (17.2 wt.%) of electrically conductive AgNPs achieved in host particles. Therefore the present work demonstrate that a careful selection of both structural (particle morphologies aspect ratio internal pore diameter surface functionalization) and compositional (enzyme loading electron mediator AgNP loading) variables leads to improved performances of both biosensor and chemical sensor in terms of desirable sensor-characteristics like linearity sensitivity selectivity and speed of response.