Graphene Oxide (GO) Coated Impedimetric Gas Sensor for Selective Detection of Carbon Dioxide (CO₂) With Temperature and Humidity Compensation

Carbon Dioxide Sensing—Biomedical Applications to Human Subjects

“…More recently, a similar approach has been used with graphene as the sensing material instead of a metal oxide film [ 192 , 193 ] and—as is the case for metal oxide-based sensor—the working principle of such sensors is also a debated topic. Overall, graphene acts as a room-temperature p-type semiconductor and can be used either in a purely conductometric setup—measuring the bulk resistance or impedance of the graphene layer [ 194 , 195 , 196 ]—or in a Field-Effect Transistor (FET) setup—of which graphene is the canal [ 197 ]. However, the interaction of the CO molecule with the graphene layer is not exactly known, and different competing theories have been proposed.…”

“…Graphene has been used both as a pristine material [ 194 , 200 , 201 , 202 ] and in its oxidised form [ 196 , 203 ] for CO sensing. Additionally, other authors even considered the fabrication of composite sensors, combining graphene with polyethyleneimine [ 195 ] or metal oxides—such as Al O [ 204 ], Sb O [ 205 ], In O and NiO [ 206 ] with mitigated results.…”

“…Additionally, other authors even considered the fabrication of composite sensors, combining graphene with polyethyleneimine [ 195 ] or metal oxides—such as Al O [ 204 ], Sb O [ 205 ], In O and NiO [ 206 ] with mitigated results. Indeed, the performance of graphene-based devices for CO sensing suffers from a high cross-sensitivity to a variety of other gases—e.g., N , O , NH , CO or H [ 196 , 200 , 201 ]—and humidity [ 201 , 202 , 207 ]. Encouragingly, however, Akther et al [ 196 ] recently reported temperature and humidity corrections for graphene oxide-based CO sensor, with a mean error below 3% on the full 400–4000 ppm scale, and a response time of 3–5 s, despite showing some degree of cross-sensitivity towards other gases.…”

Recent Progress of Toxic Gas Sensors Based on 3D Graphene Frameworks

“…There have been many reports on the application of graphene in gas sensors, including pure graphene [23][24][25][26] and graphene composite materials [27][28][29][30][31]. There are many factors affecting graphene-based sensors, including: synthetic method [32][33][34], chemical structure [35][36][37], interlaminar structure [34,38], testing environment [39][40][41][42], and surface properties [43][44][45][46][47]. Due to the π-π accumulation and Van Der Waals force binding between graphene, the 2D graphene nanocomposites tend to agglomerate, resulting in the reduction of specific surface area [48][49][50].…”

Carbon Dioxide Sensor Module Based on NDIR Technology

“…Wang et al from Jilin University designed and used a rotating system based on a stepping motor and a single reflector spherical lens to realize and enhance the detection of multiple gases, including CH 4 , CO 2 , and CO [ 14 ]. However, the most interesting factor is that the gas sensor is easily affected by environmental factors, such as temperature and humidity, so it should have the advantages of better anti-interference ability and a stable and reliable system [ 15 , 16 , 17 ]. Traditional sensors or detection systems mostly adopt hardware compensation.…”