LI Jun-li,HE Meng-yao,YAN Xin-yu,et al.Preparation of Boron-doped Carbon Dots with High Fluorescence Quantum Yield and Its Application for Determination of 2,4,6-Trinitrophenol in Water[J].Journal of Instrumental Analysis,2023,42(09):1127-1133.
LI Jun-li,HE Meng-yao,YAN Xin-yu,et al.Preparation of Boron-doped Carbon Dots with High Fluorescence Quantum Yield and Its Application for Determination of 2,4,6-Trinitrophenol in Water[J].Journal of Instrumental Analysis,2023,42(09):1127-1133. DOI: 10.19969/j.fxcsxb.23042801.
Preparation of Boron-doped Carbon Dots with High Fluorescence Quantum Yield and Its Application for Determination of 2,4,6-Trinitrophenol in Water
2,4,6-Trinitrophenol(TNP) is a commonly used nitroaromatic explosive. Excessive use will cause serious pollution to soil and groundwater. TNP not only causes a series of environmental problems,but also has many negative effects on the human body. So far,many analytical methods have been applied to the determination of nitroaromatic explosives,such as high performance liquid chromatography(HPLC),mass spectrometry(MS),and electrochemical methods. However,these methods have some drawbacks,such as high cost,complicated sample pretreatment,and expensive instruments. It is of great significance to develop a simple,sensitive and selective method for the detection of TNP. In order to solve this problem,a rapid detection and analysis method of TNP was established based on the inner filter effect(IFE) using B-doped carbon dots(B-CDs) as fluorescent probes. In this study,B-CDs with fluorescence quantum yield of 51.43% were prepared by one-step hydrothermal method using 3-aminophenylboronic acid(3-APBA) as raw material. The morphology and particle size distribution of B-CDs were observed by transmission electron microscopy(TEM). The functional groups on the surface of B-CDs were investigated by FT-IR spectroscopy. The elemental composition and chemical state of B-CDs were studied by X-ray photoelectron spectroscopy(XPS). The optical properties of B-CDs were investigated by fluorescence spectroscopy and ultraviolet-visible absorption spectroscopy. In addition,the effects of pH,salt concentration and temperature on the fluorescence intensity of B-CDs were studied. It was found that the fluorescence emission peak of the prepared B-CDs overlapped with the ultraviolet-visible absorption peak of TNP. According to the fluorescence lifetime results,it was judged that there was an internal filtering effect between the two. The pH 6.0 and room temperature were selected as the optimal experimental conditions. Under the optimal experimental conditions,the fluorescence intensity of B-CDs decreased regularly in the range of 0.5-100 μmol/L TNP concentration. The TNP concentration showed a good linear relationship with the quenching degree lg(,I,0,/,I,),and the linear equation was lg(,I,0,/,I,)= 0.01,c,+0.022 86(,r,2, = 0.999 78). The detection limit was calculated to be 86 nmol/L according to the 3,σ, rule. The method was successfully applied to the determination of TNP in environmental water samples. The spiked recoveries of the actual samples were 95.1%-110%,and the relative standard deviation(RSD) was in the range of 1.0%-3.9%. The TNP analysis method based on IFE mechanism is simple,sensitive and selective.