GO/μ -- IDEs/p-Si Based Real Time Sensors for F-Detection in Natural Drinking Water

Molecular interaction between Graphene oxide (GO) synthesized using chemical oxidation of graphite and lithography patterned aluminum (Al) micro-interdigitated electrodes (μ-IDEs) on p-Si for aqueous fluoride ion (F^-) sensor is demonstrated. The strong hydrogen bonding and molecular adsorption of aqueous Fonto the active hydrophilic sites (hydroxyl, carbonyl, carboxyl, epoxy) present in GO integrated with Al-μ-IDEs is examined using electrical characterization (current-voltage, capacitance-frequency). The current for GOAl-μ-IDEs shows almost 2.3, 4.7 times increase for F̅solution of 0.1 and 1 ppm with respect to GO. Additionally, the integration of GO-Al-μ-IDEs shows almost three order increase in the current for F̅ solution of 10 ppm. The adsorption of F̅ onto the GO film results the increase in charge carriers and finally results the increase in the output current response. Owing to the saturation in the binding sites present onto GO for F̅ solution of 100 ppm, the F̅ penetrate the GO film and results the decrease in current of the sensor. Thus, the cost effective, easy processability and selectivity of proposed GO-integrated Al-μ-IDE based real time sensors have a great potential to be a forefront sensor for detection of aqueous F̅ present in natural drinking water.