Alcohol Recognition by Flexible, Transparent and Highly Sensitive Graphene-Based Thin-Film Sensors

Xuezhu Xu,Qian Ma,Gilles Lubineau,Yangyang Xin,Long Jiang,Jian Zhou

doi:10.1038/s41598-017-04636-2

Abstract

Chemical sensors detect a variety of chemicals across numerous fields, such as automobile, aerospace, safety, indoor air quality, environmental control, food, industrial production and medicine. We successfully assemble an alcohol-sensing device comprising a thin-film sensor made of graphene nanosheets (GNs) and bacterial cellulose nanofibers (BCNs). We show that the GN/BCN sensor has a high selectivity to ethanol by distinguishing liquid–phase or vapor–phase ethanol (C2H6O) from water (H2O) intelligently with accurate transformation into electrical signals in devices. The BCN component of the film amplifies the ethanol sensitivity of the film, whereby the GN/BCN sensor has 12400% sensitivity for vapor-phase ethanol compared to the pure GN sensor, which has only 21% sensitivity. Finally, GN/BCN sensors demonstrate fast response/recovery times and a wide range of alcohol detection (10–100%). The superior sensing ability of GN/BCN compared to GNs alone is due to the improved wettability of BCNs and the ionization of liquids. We prove a facile, green, low-cost route for the assembly of ethanol-sensing devices with potential for vast application.

Highlights

Cellulosic nanofibers are one of three emerging nanomaterial fibers that can be used for device assembly[11]
The bacterial cellulose nanofibers (BCNs) were obtained by grinding these BC pellicles in a kitchen blender followed by mild stirring assisted with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical mediation
The extraction of BCNs is similar to that for plant-based cellulose nanofibers[33], the difference is that BCNs are based on bacterial cellulose pellicle, which can be grown on a large scale at very low cost

Summary

Introduction

Cellulosic nanofibers are one of three emerging nanomaterial fibers (cellulosic, carbon and inorganic nanofibers) that can be used for device assembly[11]. BCN film sensors practically, we used sensitivity (∆R/R, %) to evaluate their sensing performance when exposed to target liquids or vapors: Sensitivity = ∆R = Rin target − Rin air × 100% , R This simple model demonstrates that a thin-film GN/BCN sensing device has high sensitivity when exposed to target liquids.

Results

Conclusion