ABSTRACT
The chemiluminescence (CL) reaction between ozone and 3,6-dihydroxynaphtha-2,7-disulphonate (DNDS) was found under alkaline conditions. Therefore, a novel CL system for ozone detection was established. The CL signal of the CL system is weak, and the CL signal is enhanced by adding nonionic surfactants. It was found that adding 16.4 g/l Triton X-100 can enhance the CL signal. The CL reagent activated by ultraviolet (UV) light produced a CL signal was nearly 10 times stronger than the CL reagent not activated by UV light; the CL signal was enhanced by adding 8 g/l NaHCO3 to the CL reagent irradiated by UV light. Through the optimization of these test conditions, a high-selectivity, high-sensitivity online detection method for ozone CL was established. The linear range was 0.5-150 ppbv, and the limit of detection (LOD) was 0.092 ppbv (S/N = 3).
Subject(s)
Luminescence , Ozone , Luminescent Measurements/methods , Indicators and Reagents , Limit of DetectionABSTRACT
In this paper, nylon microfiber fabric with a heterogeneous chemiluminescence system was used for the synthesis of gold nanoparticles (AuNPs) for the first time, and it was used to enhance the online detection of carbon dioxide (CO2) by heterogeneous chemiluminescence. Nylon microfiber fabric was chosen as the gas-liquid heterogeneous chemiluminescence micro reaction interface. The thermal reduction method prepared the micro reaction interface with in situ synthesized AuNPs. The solution of H2O2 and KOH forms a liquid film on the surface of the micro reaction interface, and a heterogeneous chemiluminescence reaction occurs when CO2 flows through the surface of the liquid film. The AuNPs supported in situ on the micro reaction interface act catalytically and enhance the chemiluminescence signal for CO2 detection. In this way, AuNPs can be used repeatedly in the chemiluminescence reaction, avoiding the waste of precious metal nanoparticles and reducing the detection cost. Under the optimal conditions, CO2 has a good linear relationship with the chemiluminescence signal in the range of 10-20 000 ppm (v/v). The correlation coefficient R2 is 0.9963, the detection limit is 0.35 ppm (v/v), and the relative standard deviation is 1.79%. This approach provides an entirely new technological platform for the development of functional fabrics and the maximum utilization of precious metal nanoparticles.
ABSTRACT
The determination of the ozone concentration in the atmosphere is an urgent need but most current methods are limited by large-scale equipment or complex procedures. Herein, a gas-liquid chemiluminescence (GL-CL) assay based on a portable GL-CL detector platform was reported for the fast and sensitive online determination of ozone. Graphene quantum dots (GQDs) and Triton X-100 were employed to synergistically enhance the CL intensity of chromotropic acid (CA)-ozone. The increase was about seven-fold upon the addition of GQDs and Triton X-100. The potential enhancement mechanism was also investigated. The speculated CL enhancement mechanism was that GQDs could catalyze dissolved oxygen in the CA solution to produce more free radicals in the presence of UV-light, and these radicals converted CA into more active compounds that could react with ozone and emit photons. The free radicals, active compounds and luminophores were protected from water quenching by micelles produced by dissolving Triton X-100 in water and as a result, CL was markedly enhanced. Most importantly, the response time of the GL-CL detector platform towards ozone was less than 0.5 s. Based on this outcome, a GL-CL assay for detecting atmospheric ozone was successfully developed with a linear range from 0.1 to 150 ppbv and a detection limit of 0.02 ppbv. This work provides a rapid and sensitive method for the online measurement of ozone, and has great potential in environmental applications; the potential applications of GQDs and Triton X-100 in the field of GL-CL have also been highlighted.
