超小尺寸聚焦硫量子点荧光传感探针的制备及传感应用

Simple Synthesis of Ultra-small Size Focused Sulfur Quantum Dots for Fluorescence Sensing

采用简单的组装-裂变法和透析后处理技术相结合的方法,制备了一种超小尺寸聚焦的荧光硫量子点(SQDs)。采用透射电子显微镜(TEM)、X射线能谱(EDX)、紫外-可见吸收光谱(UV-Vis)和荧光光谱对所制备的SQDs进行了表征。结果表明,平均粒径为2.2 nm的SQDs在水溶液中具有非激发波长依赖特性和光学稳定性。并且Fe^(3+)会显著猝灭SQDs的荧光,推测其猝灭机制为内滤效应(IFE)。基于Fe^(3+)对该SQDs产生的荧光猝灭效应,成功构建了一种简便、高选择性和高灵敏度的检测Fe^(3+)的荧光分析平台。该方法检测Fe^(3+)的线性范围为5~600μmol/L,检出限(LOD)为1.19μmol/L,并成功实现了血清样本中Fe^(3+)的检测。该方法操作简单、成本低,且具有高灵敏度、高选择性等优点,为SQDs及其相关探针制备提供了一种简单有效的方法,在临床诊断中具有较好的应用前景。

A facile assembly-fission method combined with dialysis post-treatment strategy was adopted to prepare a kind of ultra-small size focused fluorescent sulfur quantum dots(SQDs).The as-prepared SQDs were characterized by transmission electron microscopy(TEM),energy-dispersive X-ray spectroscopy(EDX),UV-Vis absorption spec⁃trometry(UV-Vis)and fluorescence spectrometry.The photoluminescence properties of the SQDs were investigated in detail,which indicated that the SQDs with the average diameter of 2.2 nm exhibited an excitation-independent emission and an optical stability in aqueous solution.Meanwhile,the fluorescence of the SQDs could be quenched by Fe^(3+)significantly,and the mechanism for the fluorescence quenching was via inner filter effect(IFE).Based on the fluorescence quenching effect of the Fe^(3+)/SQDs system,a facile fluorescence sensing platform was successfully con⁃structed for the highly selective and sensitive detection of Fe^(3+).The proposed SQD-based sensor showed a wide re⁃sponse to Fe^(3+)in the range of 5-600μmol/L,with a detection limit(LOD)of 1.19μmol/L.In addition,this meth⁃od,with significant advantages of high sensitivity,high selectivity,simplicity and economy,was successfully ap⁃plied to the detection of Fe^(3+)in human serum,avoiding the deficiencies of complex sample preparation and expensive detection conditions.Thus,this method has a potential application prospect in clinical diagnosis,and opens up a new way for the design of effective fluorescent probes for other biologically related targets.