Starch-Mediated Immobilization, Photochemical Reduction, and Gas Sensitivity of Graphene Oxide Films

Abstract

This work unveils the roles played by potato starch (ST) in the immobilization, photochemical reduction, and gas sensitivity of graphene oxide (GO) films. The ST/GO films are assembled layer by layer (LbL) onto quartz substrates by establishing mutual hydrogen bonds that drive a stepwise film growth, with equal amounts of materials being adsorbed in each deposition cycle. Afterward, the films are photochemically reduced with UV irradiation (254 nm), following a first-order kinetics that proceeds much faster when GO is assembled along with ST instead of a nonoxygenated polyelectrolyte, namely, poly(diallyl dimethylammonium) hydrochloride (PDAC). Finally, the gas-sensing performance of ST/reduced graphene oxide (RGO) and PDAC/RGO sensors fabricated via LbL atop of gold interdigitated microelectrodes is evaluated at different relative humidity levels and in different concentrations of ammonia, ethanol, and acetone. In comparison to the PDAC/RGO sensor, the ones containing ST are much more sensitive, especially when operating in a high-relative-humidity environment. An array comprising these chemical sensors provides unique electrical fingerprints for each of the investigated analytes and is capable of discriminating and quantifying them in a wide range of concentrations, from 10 to 1000 ppm.

Bias Stress in Organic Thin-Film Transistors Towards Low-Cost Flexible Gas Sensors

“…A secondary dry N2 flow was responsible to dilute the primary one and adjust the RH. More details can be found in [40].…”

Stability of Polythiophene-Based Transistors upon Bending for Gas Sensing Applications

“…P3HT can be also integrated to poly(2,5-bis(3tetradecylthiophene-2-yl)thieno[3, 2-b]thiophene) (PBTTT), and graphene oxide composites (e.g. metal oxides and starch) to form e-noses [38][39][40]. One of the most interesting application lies in the detection of water contaminants [41].…”

A Review of Inkjet Printed Graphene and Carbon Nanotubes Based Gas Sensors

“…A high mobility, near-ballistic transport and stability at room temperature make graphene an ideal material for sensing applications, particularly gas/vapor detection [ 66 ]. Thus, graphene-based gas sensing device development has increased exponentially, and the number of published papers has sharply increased since 2007 [ 9 , 10 , 14 , 17 , 19 , 39 , 40 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 ]. In this section (Graphene-Based Gas Sensors), we will focus on inkjet printing of graphene-based gas/vapor sensor and their performance.…”

“…The dispersant and the stabilizing agents reduce the conductivity in the oxygenated species. Improvement regarding non-graphene components, such as using a proper conductivity polymer or even starch in the ink solution, tends to promote the performance of the overall sensor [ 75 ].…”

“…There have been several groups that have extensively studied the role of defects on the sensing mechanism of the graphene-based devices [18][19][20]27,31,36,[117][118][119][120][121][122]. Defects such as film thickness, crystalline structure, porosity, wrinkles, grain boundaries, and external substrate defects all greatly affect the sensing performance of the sensor [19,20,22,75,76,123,124]. help in obtaining rapid response rates.…”