Ultra-Sensitive Non-Enzymatic Ethanol Sensor Based on Reduced Graphene Oxide-Zinc Oxide Composite Modified Electrode

• Published in: IEEE sensors journal Vol. 18; no. 5; pp. 1844 - 1848
• Main Authors: Sha, Rinky, Puttapati, Sampath Kumar, Srikanth, Vadali V. S. S., Badhulika, Sushmee
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Chemical sensors; Chemical synthesis; electrochemical sensor; Electrodes; Ethanol; ethanol sensor; Graphene; II-VI semiconductor materials; Reduced graphene oxide; Sensitivity; Sensors; Zinc oxide; Zinc oxides; ZnO
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2017.2787538

In this paper, we report a reduced Graphene Oxide (rGO)-Zinc Oxide (ZnO) composite-based nonenzymatic ethanol sensor with an ultra-high sensitivity of 508.91 μAmM -1 cm -2 which is, to the best of our knowledge, ~8 folds higher than previously reported electrochemical ethanol sensors. The rGO-ZnO composite was synthesized by a wet chemical method wherein the reduction of GO and intimate interfacial contact between ZnO NPs and rGO were achieved simultaneously. The sensing of ethanol was explicated by means of current-potential (I-V) technique. The sensor exhibited reproducible response with insignificant variations in current tested across multiple electrodes and responded linearly to ethanol in the range of 0.5-5 mM (R 2 = 0.957). The sensor also showed lower limit of detection. The significant improvement in sensitivity is attributed to the improved surface activity and faster charge separation owing to formation of the nano-Schottky barrier at rGO-ZnO interface. This approach is beneficial as it eliminates the use of conducting binder along with the functional material for ethanol sensing. This ultra-sensitive, binder free rGO-ZnO-based sensor offers a simple, low cost approach for ethanol detection in food, pharmaceutical, bio fuel industries, and environmental analyses.