A Highly Sensitive and Selective Isobutyraldehyde Sensor Based on Nanosized Sm₂O₃ Particles

A highly sensitive and selective sensor for isobutyraldehyde (IBD) is demonstrated based on intensive cataluminescence (CTL) emission from the surface of nanosized Sm₂O₃ particles. The characteristics and optimum conditions for the CTL sensor, including the working temperature, wavelength, and flow rate, were investigated in detail. Under the optimized experimental conditions, the CTL intensity varied linearly with the concentration of IBD, in the two-order-of-magnitude range of 0.015-3.9 μg/mL, with a correlation coefficient (r) of 0.99991 and a limit of detection (LOD), at a signal-to-noise ratio (S/N = 3) of 4.6 ng/mL. The sensor was quite specific: butyraldehyde, methanol, ethanol, acetone, formaldehyde, acetaldehyde, benzene, ethylbenzene, and cumene could not produce significant CTL intensities; specifically, butyraldehyde, ethanol, acetone, and acetaldehyde produced low CTL intensities, with values that were 3.8%, 2.8%, 0.60%, and 0.57% that of IBD. As a test of sensor stability, we found that the relative standard deviation (RSD) of 30 measurements of the CTL at an IBD concentration of 1.6 μg/mL within a period of 72 h was 2.2%, indicating good stability and long service life of the sensor. The sensor was tested against spiked samples containing IBD, and recoveries between 89.7% and 97.4% were obtained with an RSD of 6.1%-8.6%. The performance of the sensor indicated its utility for practical sample analysis.