Contents Introduction
Although considered as moderately toxic in comparison to other highly poisonous gases, CO detection has always been of vital importance, as it lacks color, odor, or taste and is present in numerous natural and artificial environments [1]–[3]. Thus, CO sensors are highly demanded, especially portable ones which are small, low-powered, and inexpensive. Many technologies and devices (chemiresistive, optical, electrochemical, etc.) have been developed to detect or monitor the leakage of CO [4]–[6]. These systems suffer from drawbacks such as low sensitivity, poor selectivity, or short service time. Thus, developing high performance CO sensors is of great importance.
