摘要
以单质硫⁃乙二胺混合液作为前驱体,采用简单的一步溶剂热法制备了高荧光效率的硫量子点(SQDs)。制得的SQDs具有优异的水溶性,其粒径范围为1.6~3.8 nm,呈现近单分散尺寸分布。SQDs的发射峰不随激发波长的改变而变化,当激发波长为340 nm时其显示出最强的荧光,荧光量子产率可达87%。同时,该SQDs还具有良好的荧光稳定性,改变溶液的pH或室温静置1个月,其荧光强度都没有明显降低。进一步的性能研究发现,该SQDs可以作为一种高灵敏度和高选择性的荧光探针来检测对硝基苯酚(4⁃NP),这是由于4⁃NP与SQDs之间存在内滤效应,4⁃NP能够有效猝灭SQDs的荧光。当4⁃NP浓度在2~85μmol/L范围内时,SQDs的相对荧光强度(I/I_(0))与4⁃NP的浓度呈现良好的线性关系,检测限达到了73.4 nmol/L。真实水样检测结果也证实该SQDs可以有效检测环境中的4⁃NP。
As a new class of metal-free fluorescent nanomaterials,sulfur quantum dots(SQDs)have attracted increasing attention because of their unique composition,excellent optical properties and low toxicity.However,the SQDs usually suffer from the drawbacks of low fluorescence quantum yield(QY)and long preparation time,which significantly limit the practical application of SQDs.In this paper,we report a simple and viable method to prepare SQDs with high QY based on the one-step solvothermal treatment of elemental sulfur-ethylenediamine(EDA)precursor at 175℃for 4 h.The prepared SQDs exhibited excellent water solubility and nearly monodisperse size distribution with size in the range of 1.6-3.8 nm.Different from other reported SQDs,the obtained SQDs showed excitation-independent emission behavior.The emission peak of the SQDs did not change with the variation of excitation wavelength.The maximum emission intensity was achieved when the excitation wavelength was 340 nm.Moreover,the fluorescence QY of SQDs was determined to be as high as 87%,which is much higher than other reported SQDs.The SQDs also displayed good fluo⁃rescence stability.When the solution pH was changed in the range of 4-9 or the SQDs solution was stored at room temperature for one month,the fluorescence intensity of SQDs did not change signifi⁃cantly.Furthermore,the SQDs can be used as an effective fluorescent probe for highly sensitive and selective detection of 4-nitrophenol(4-NP).Owing to the presence of inner filter effect,the 4-NP can effectively quench the fluorescence of SQDs.When the concentration of 4-NP was in the range of 2-85μmol/L,there was a good linear relationship between the relative fluorescence intensity(I/I_(0))of SQDs and the concentration of 4-NP.The limit of detection was calculated to be as low as 73.4 nmol/L.In addition,the SQDs were also successfully employed to sense 4-NP in tap water and river water with satisfactory performance.
作者
黄铮钰
黄泽明
周立
HUANG Zheng-yu;HUANG Ze-ming;ZHOU Li(College of Materials Science and Engineering,Guilin University of Technology,Guilin 541004,China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2022年第6期952-960,共9页
Chinese Journal of Luminescence
基金
国家自然科学基金(U21A2097)
广西自然科学基金(2017GXNSFFA198002)
广西八桂学者计划资助项目。
关键词
硫量子点
荧光探针
检测
对硝基苯酚
内滤效应
sulfur quantum dots
fluorescent probe
detection
4-nitrophenol
inner filter effect
