Novel strategy and highly sensitive cataluminescence gas sensor for methallyl alcohol detection based on La2O3/α-Al2O3 composite materials

Methallyl alcohol (MA), which is a common volatile organic compound, in vapor form can cause respiratory irritation, headache, nausea, and vomiting. Therefore, the development of a highly selective, excellently sensitive, and efficient sensor for rapidly identifying trace MA is essential. In this study, a La 2 O 3 /α-Al 2 O 3 composite with excellent cataluminescence (CTL) activity in the presence of MA was successfully synthesized. The CTL sensor based on as-prepared La 2 O 3 /α-Al 2 O 3 exhibited high selectivity for MA vapor as well as response and recovery times of 1 and 6 s, respectively. Under the optimal conditions for MA detection, the La 2 O 3 /α-Al 2 O 3 sensor exhibited a linear range of 0.0025–0.50 mg/L (correlation coefficient, R 2 = 0.998) and a low limit of detection of 0.61 μg/L at a signal-to-noise ( S/N ) = 3. The La 2 O 3 /α-Al 2 O 3 sensor was also used to determine the MA content in spiked samples and volatile gases generated from a medicine cabinet. Excellent recoveries in the range of 82.5–107% were obtained, with a corresponding relative standard deviation ( n  = 5) in the range of 2.1–4.7%. Furthermore, the CTL sensing mechanism was investigated through density functional theory and high-performance liquid chromatography-ultraviolet analyses.