ZnO-WO3 Mixed Metal Thin Film Capacitive Biosensor for Food Quality Measurement

The biotin biomolecule has been sensed with the help of designed MEMS sensor. It takes advantage of MEMS technology where ZnO-WO
3
mixed nanomaterial is used with cavity structure as a capacitive biosensor for higher sensitivity. The freshness of foods where biotin is mostly present (> 10ug/100g) can be easily detected using the proposed structure. The proposed structure is analyzed using Intellisuit-7 simulator and further it is fabricated using sol-gel method and cavity design techniques. When the sensor is placed inside the food the overall sensor capacitance changes with time as the food quality gets deteriorated. The reason is change of dielectric (Є
k
) value. Due to homogeneous structure of the biosensor it produces linear response in terms of change of dielectric with time. Further, SEM and XRD processes are used to analyze the distribution of molecules at micro scale level. Significant capacitance shifts is observed for change of time span of 12 days due to biotin’s dielectric change which directly shows quality standard of food.