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The cataluminescence (CTL) reaction detects the presence and concentration of toxic volatile organic compounds by detecting the luminescence intensity of the different components of the gas mixture. In our study, a cataluminescence online sensor system based on LaCO 3 OH microspheres was developed for the low concentration detection of volatile organic compounds. Multi-dimensional CTL test was carried out to analyse the correlation characteristics of heterogeneous analytes among the catalytic activity, selectivity, sensitivity, response/recover time, stability, and photoelectric signals by changing the parameters of wavelength, flow rate, temperature, and response time under the optimal conditions (280 mL/min, 180ºC, and 480 nm). Due to noise interference received by the CTL signal, the weak CTL signal was filtered based on the time-frequency characteristics of the CTL pattern signal power frequency interference and background noise. Next, this study also studied the mechanism action of the cataluminescence sensor based on LaCO 3 OH microspheres for gas detection, including ethyl ether, acetone, chloroform, and formaldehyde. The principal component analysis (PCA) algorithm was adopted to analyse the CTL patterns, after threshold filtering, the total variance was improved from 89.23% to 98.78% and each vapour gave its unique CTL patterns. Moreover, clustering and identification are discussed to analyse the results, including Hierarchical Cluster Analysis (HCA) and Radial Basis Function Neural Networks (RBFNN), was also discussed. The excellent cluster and recognition ability indicate the feasibility of this CTL sensor for volatile compound determination. • A LaCO 3 OH-microspheres-based cataluminescence sensor was developed for the detection of VOCs firstly. • Multi-dimensional analytes test was carried out among the catalytic activity, selectivity, sensitivity, response/recover time, stability, and photoelectric signals. • Studied the mechanism action of the cataluminescence sensor based on LaCO 3 OH microspheres for gas detection. • The total variance of PCA increased from 89.23% to 98.78% after filtering out the background noise of CTL signal. [ABSTRACT FROM AUTHOR]

Portable sensor system was constructed for detection of acetone vapor based on the cataluminescence (CTL) theory. Excellent microspheres were prepared successfully which increased the contact probability with vapors. The instrument architecture, optimal experiment conditions and measurement characteristics were discussed in detail. The results showed the CTL sensor instrument exhibited excellent CTL properties including visible intensity, high signal/noise (S/N) values, short response time (within 2 s) and recovery time (within 3 s). The sensor instrument covered a linear test range from 5 ppm to 2500 ppm, while the sensor showed non-linearity when concentration ranged from 2500 ppm to 8000 ppm. Furthermore, the sensor system showed outstanding selectivity to acetone compared with other ten kinds of common vapors. Moreover, the CTL sensor also showed an excellent response for H 2 S, the CTL performance of H 2 S under different wavelength and temperature was also discussed. The excellent sensing and online detecting properties proved this sensor instrument to be an excellent candidate for real-time gas contaminant detection. Finally, the sensing control processes and monitoring software interface was also presented. [ABSTRACT FROM AUTHOR]

• The CTL sensor instrument could response to ethyl ether under 180 °C, which was lower than most of the reported CTL reaction temperatures. • The linear detection range was wide, ranging from 10 ppm to 5800 ppm (R = 0.9978, n = 7), and the detection limit was also low (4.3 ppm). • The CTL sensor showed the response time of 4 s and recovery time of 8 s, which was relatively short. • The pattern recognition results showed the analytes could be classified clearly. The low reaction temperature, excellent sensitivity, selectivity, stability and recognition performance indicated this CTL sensor was ideal for gas contaminants detection in confined spaces for the Internet of Things. Gaseous cataluminescence (CTL) sensor instrument was developed for detecting and measuring pernicious gases such as ethyl ether, acetone, n-hexane, chloroform by using aluminum/iron oxides composites. The materials synthesis, apparatus and software, optimal conditions (flow rate, wavelength, temperature and concentration), selectivity and stability were thoroughly studied. The results indicated the CTL sensor instrument could response to ethyl ether under 180 °C, which was lower than most of the reported CTL reaction temperatures. In addition, the results showed that the linear detection range was wide, ranging from 10 ppm to 5800 ppm (R = 0.9978, n = 7), and the detection limit was also low (4.3 ppm). Moreover, for ethyl ether detection, the CTL sensor showed the response time of 4 s and recovery time of 8 s, which was relatively short. The pattern recognition methods included PCA, KPCA were selected for evaluating the recognition performance of this CTL sensor, results showed the analytes could be classified clearly. The low reaction temperature, excellent sensitivity, selectivity, stability and recognition performance indicated this CTL sensor was ideal for gas contaminants detection in confined spaces for the Internet of Things. [ABSTRACT FROM AUTHOR]

Gaseous sensor system was developed for the detection of sulfur hexafluoride vapor based on its cataluminescence (CTL) emission by using coral-like Zn-doped SnO 2 composite. The test architecture, experiment characteristics and optimal conditions were studied in detail under optimized experiment conditions. Results showed that the gas sensor system covered a linear detection range from 8 mg/L to 5600 mg/L (R = 0.9963, n = 7) with a detection limit of 6.2 mg/L (S/N = 3), which was below the standard permitted concentration. The sensor showed a rapid response of 2 s and a recovery time of 30 s, respectively. Moreover, pattern recognition method was used to test the recognizable performance of this sensor, which has found that analyte can be distinguished clearly. As sensing materials for a CTL gas sensor, this coral-like Zn-doped SnO 2 demonstrates excellent CTL behavior (that is, high sensitivity, superior selectivity to sulfur hexafluoride compared with other eleven kinds of common volatile organic compounds (VOCs) as well as a fast response and recovery). The excellent sensing properties including improved sensitivity, selectivity and stability proved this sensor to be a promising candidate for detecting gas contaminants. [ABSTRACT FROM AUTHOR]

Abstract: A novel cataluminescence (CTL)-based sensor array consisting of 16 types of catalytic nanomaterials was developed for the determination and identification of volatile organic compounds (VOCs). The sensing nanomaterials, including nano-sized metal oxides, decorated nanoparticles, carbonates, and nano-sized AgSe have been selected carefully. A 4×4 array was integrated by depositing these nanomaterials onto the ceramic chip. Dynamic and static analysis methods were utilized to characterize the performance of the sensor array to 12 kinds of VOCs. Each compound gives its unique CTL pattern after interaction with the sensor array, which can be employed to recognize VOCs. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to analyze the CTL patterns. PCA was conducted to classify the drug precursor gas and the plots showed that the groups were well classified. In addition, the patterns obtained at different working temperature and the analytical characteristics of array were investigated. The CTL-based sensor array shows promising perspective for the recognition and discrimination of VOCs. [Copyright &y& Elsevier]