Methods and mechanisms of gas sensor selectivity

The selectivity of a sensor is the ability to discriminate the target from the interference molecules and display a target-specific sensor response. It is a critical trait for gas sensors that are used in real-time air pollution control, hazardous materials detection, food quality inspection and personal health monitoring. Attaining high target selectivity ensures that sensors will exhibit accurate information about the existence and concentration of a target gas, which is essential for reliable sensor response. To obtain target selectivity, it is critical to determine the optimum modification technique and receptor materials as well as to understand how each method works and how it could be designed for a specific target. For this purpose, in this review we present the working principles of the three leading chemical modification methods including catalyst decoration, composite formation, and surface functionalization, as well as the selection criteria of various recognition materials. Throughout the report, we offer a rich apprehension of these techniques by providing mechanistic insights, application areas, advantages, disadvantages, and plausible applications for the invention of the target-specific gas sensors.