A 2D SnSe 2 layered film-based gas detector incorporating a floating-gate device coupled with metal interconnect wiring structures is proposed and demonstrated for the first time. Linear amplification can be readily implemented using a coupling ratio design, which refers to the capacitance ratio between the gate and device in the sense amplifier circuits. A sensitivity of 102 mV ppm −1 can be obtained using the 2D SnSe 2 layered film with a thickness of 10 nm. The 2D SnSe 2 layered film-based complementary metal-oxidesemiconductor (CMOS) gas detector features highly sensitive, wide, and adjustable dynamic ranges with a real-time response of the sub-ppm detection limit on NO 2 gas. In addition, the synthesis process of the SnSe 2 layered film can occur at a low temperature and be operated at room temperature. Furthermore, 3 × 3 gas detector arrays with peripheral circuits demonstrate the functionality of multiple gas detection simultaneously and 16 × 16 arrays with a decoder and other peripheral circuits are constructed and simulated, providing the spatial distribution of the gas concentration in a specific region. The performance of the proposed detector is comparable to that of the other state-of-the-art gas sensors.

systems of organisms are related to various chemical reactions. Therefore, the concentration of ions is critical for balancing these interactions. pH values can serve as an indicator for abnormality diagnosis. For example, the pH of blood should range from 7.35 to 7.45 regulated by the lungs and kidneys for metabolic processes in the human body. Acidosis or alkalosis occurs when the pH of blood is out of this range. It can be inferred that the lungs or kidneys cannot maintain the pH of blood within the healthy range. In another example, heatstroke will occur when the body temperature increases to 40 °C or beyond, resulting in neurological dysfunction, coma, seizures, and even death. The pH value of the surface of healthy skin is within the range of 4.2 to 5.6. Therefore, the pH value of the skin surface can reveal whether a heatstroke has occurred in a person. [6] In addition to the pH value, the sodium ion is another crucial indicator in balancing and operating neuromuscular activities. Typically, the sodium concentration in the human blood is between 135 and 145 mmol L −1 . If the sodium concentration is out of this range, fatigue, nausea, headache, and drowsiness will be experienced in the human body. ByThe ORCID identification number(s) for the author(s) of this article can be found under