Cataluminescence sensing of carbon disulfide based on CeO2 hierarchical hollow microspheres

Enhanced Cataluminescence Sensor Based on SiO2/MIL-53(Al) for Detecting Isobutylaldehyde

A simple, rapid, and reliable method for detecting harmful gases is urgently required in environmental security fields. In this study, a highly effective cataluminescence sensor based on SiO2/MIL-53(Al) composites was developed to detect trace isobutylaldehyde. The sensor was designed using isobutylaldehyde to generate an interesting cataluminescence phenomenon in SiO2/MIL-53(Al). Under optimized conditions, a positive linear relationship was observed between the signal intensity of the cataluminescence and isobutylaldehyde concentration. The isobutylaldehyde concentration range of 1.55-310 ppm responded well to the sensing test, with an excellent correlation coefficient of 0.9996. The minimum detectable concentration signal-to-noise ratio (S/N = 3) was found to be 0.49 ppm. In addition, the sensor was effectively utilized for analyzing trace isobutylaldehyde; the analysis resulted in recoveries ranging from 83.4% to 105%, with relative standard deviations (RSDs) of 4.8% to 9.4%. Furthermore, the mechanism of cataluminescence between SiO2/MIL-53(Al) and isobutylaldehyde was explored using GC-MS analysis and density functional theory. We expect that this cataluminescence methodology will provide an approach for the environmental monitoring of isobutylaldehyde.

Rapidly detecting the carcinogen acetaldehyde: preparation and application of a flower-like MoS2 cataluminescence sensor at low working temperature

In this paper, a cataluminescence (CTL) gas sensor based on flower-like molybdenum disulfide (MoS2) is developed. The experimental results show that it has high sensitivity and selectivity to acetaldehyde. The CTL sensor has the advantage of fast response; the response time is about 3 s and the recovery time is about 40 s. The optimal working temperature of this sensor is 174 °C, which is lower than that of the CTL sensors used for acetaldehyde detection in many other reports. Under the optimized conditions, the CTL signal intensity shows a good linear relationship with acetaldehyde concentration (R2 = 0.9991) within the concentration range of 40-2000 ppm, and the detection limit (LOD) is 3.75 ppm. The selectivity experiment results show that the sensor has an obvious response to acetaldehyde and a very weak response to acetic acid, and has no response to many other VOCs (ether, cyclohexane, butyl ether, carbon tetrachloride, ethanol, toluene, formaldehyde, glycerol, trichloromethane and xylene). After 8 repeated measurements for four weeks, the relative standard deviation (RSD) of the CTL sensor is 1.03%, indicating that it has good reproducibility and stability, which shows that the CTL sensor has a promising prospect for the detection of acetaldehyde.

Polyoxometalate functionalizing CeO2 hollow nanospheres as enhanced oxidase mimics for ascorbic acid colorimetric sensing

Phosphotungstic acid covered with CeO₂ hollow nanospheres (CeO₂@PTA HNSs) has been successfully prepared by a simple method, serving as highly efficient nanozymes for ascorbic acid (AA) colorimetric sensing. In virtue of the unique hollow nanostructures, oxide defects and synergic effects of CeO₂ and PTA, the proposed CeO₂@PTA HNSs present remarkable intrinsic oxidase-like activity and help capture electrons from 3,3',5,5'-tetramethylbenzidine (TMB). Due to the reducibility of AA, a promising colorimetric sensing platform based on CeO₂@PTA HNSs has been constructed for quantitative analysis of AA. The present colorimetric detection exhibits a low limit of detection, good selectivity and stability, as well as reliability in orange juice and milk. This work provides a simple surface defect engineering to prepare high-performance oxidase mimics in the application of colorimetric biosensing.

Cobalt doped nitrogenous porous carbon derived from covalent organic framework as cataluminescence catalyst for rapid determination of n-hexane in edible oil

In this work, a catalytic material of cobalt doped nitrogenous porous carbon (Co/NPC) was fabricated from covalent organic frameworks (COFs) and cobalt ion via directly carbonization. Attribute to the excellent selective catalytic performance towards n-hexane, Co/NPC was employed in cataluminescence (CTL) for rapid and sensitive determination of n-hexane. Moreover, the detection conditions of CTL were evaluated, including temperature, flow rate and detecting wavelength. Under optimized conditions, a good linear relation between signal intensity of CTL and n-hexane concentration was obtained in the linear range of 0.4-250.0 mg/L and the limit of detection (LOD, S/N = 3) was 0.13 mg/L. Furthermore, the Co/NPC based CTL sensor was successfully applied to the determination of n-hexane in edible oil samples with the recoveries in the range of 92.0%-104.0%. The method comparison results of GC/MS and CTL on real sample analysis further proved the accuracy of the developed Co/NPC based CTL method. Additionally, the possible catalytic mechanism of n-hexane on the surface of Co/NPC was investigated, assisting by GC/MS on intermediation products identification. Overall, the Co/NPC based CTL sensor has been confirmed excellent performance in the n-hexane determination, which revealing extensive application in rapid residual n-hexane analysis in edible oil.