A novel gaseous ester sensor utilizing chemiluminescence on nano-sized SiO2

A gaseous sensor for ester vapors has been developed based on their chemiluminescence (CL) on the surface of nano-sized SiO2 in an airflow. The luminescence characteristics and the optimal conditions for the determination of ethyl acetate by the sensor are investigated. Under the optimized conditions, the linear range of the CL intensity versus the concentration of ethyl acetate vapor is 20–300 ppm with a limit of detection of 3.0 ppm (3σ) and a relative standard deviation (R.S.D.) of 1.80% for eight times determination of 300 ppm ethyl acetate. There is no response or weak response when foreign substances including ethanol, methanol, hexane, cyclohexane, benzene and toluene pass through the sensor. However, acetone shows a little response which interferes slightly in the measurement of ethyl acetate. The sensor exhibits good stability and durability after 100 h reaction with 300 ppm ethyl acetate. The possible mechanism of CL from the oxidation of ethyl acetate on SiO2 is discussed based on the CL spectra and the GC–MS chromatogram of reaction products.