新型荧光碳点的制备及其在Hg2+检测中的应用

以中药材川佛手为碳源,通过高温热解产生的烟制备了平均粒径为6 nm的新型荧光碳点,其最大激发波长285 nm,最大荧光发射波长340 nm。 基于碳点良好的荧光性能及Hg²⁺对碳点荧光的猝灭作用,建立了检测Hg²⁺的新方法。 结果表明,在0.2 mol/L磷酸盐缓冲溶液(pH=7.0)中,响应时间为2 min时,该方法具有良好的选择性和抗干扰能力,检测Hg²⁺浓度的线性范围为0.2~40 μmol/L,相关系数为r=0.9996,检出限为0.052 μmol/L。 当加入2.0和40.0 μmol/L Hg²⁺到实际水样后,相对标准偏差(RSD)和加标回收率分别为0.3%~2.4%和99.5%~101.1%,可用于实际水样中Hg²⁺的分析检测。

Preparation of New Photoluminescent Carbon Dots and Its Application in Hg2+ Detection

The new photoluminescent carbon dots were prepared via high temperature pyrolysis of Chinese herbal medicine Chuan Bergamot. The average particle size of photoluminescent carbon dots is 6 nm, the maximum excitation wavelength is 285 nm, and the maximum photoluminescent emission wavelength is 340 nm. Based on the good photoluminescent properties of carbon dots and the quenching effect of Hg²⁺ on photoluminescence of carbon dots, a new method for the detection of Hg²⁺ was established. The experimental results show that the method has good selectivity and anti-interference ability with a response time of 2 min in 0.2 mol/L phosphate buffer solution(pH=7.0). The linear range of Hg²⁺ concentration is from 0.2 μmol/L to 40 μmol/L, the correlation coefficient is 0.9996, and the detection limit is 0.052 μmol/L. When 2.0 μmol/L and 40.0 μmol/L Hg²⁺ are added to the actual water sample, the relative standard deviation(RSD) and the recovery ranges are from 0.3% to 2.4% and from 99.5% to 101.1%, respectively. Therefore, it can be applied in the analysis and detection of Hg²⁺ in real samples.