Highly sensitive dimethyl ether gas sensor utilizing cataluminescence on nanosized MgO/In2O3

A gaseous sensor was developed for the determination of dimethyl ether (DME) on the basis of its cataluminescence (CTL) emission on the surface of MgO/In2O3 composite (mass ratio = 1:2). The sensor exhibited high sensitivity and selectivity to DME at a temperature of 245 °C. Under the optimized experimental conditions, the linear range of CTL intensity versus DME concentration was 50–12 000 ppm with a limit of detection of 14 ppm (signal to noise (S/N) = 3). By selecting the appropriate ratio of MgO to In2O3 and the detecting wavelength, the CTL intensities of ether and ethanol could be reduced to 7.3% and 3.9% compared with that of DME. For other compounds, including carbon tetrachloride, formaldehyde, dimethyl sulfate and methyl acetate, etc, no emissions or only very weak ones were detected. The sensor was applied to analyze samples spiked with known concentrations of DME. The concentrations of DME in all samples were well quantified with satisfactory recoveries.