Callan John F, Mulrooney Ray C, Kamila Sukanta, McCaughan Bridgeen
School of Pharmacy, The Robert Gordon University, Aberdeen, Scotland, UK.
J Fluoresc. 2008 Mar;18(2):527-32. doi: 10.1007/s10895-007-0295-9. Epub 2007 Dec 20.
A CdSe-ZnS quantum dot (QD) has been surface functionalised with 1-(2-mercapto-ethyl)-3-phenyl-thiourea in the fluorophore-spacer-receptor format typical of Photoinduced Electron Transfer (PET) based organic dye sensors. The resulting QD conjugate was tested for selectivity toward the tetrabutylammonium salts of fluoride, chloride, bromide, hydrogen sulfate and acetate. Addition of fluoride, chloride and acetate ions resulted in an approximate 90% quenching of the original fluorescence intensity, while bromide and hydrogen sulfate had almost no effect. The observed quench was attributed to an increase in the reduction potential of the receptor upon anion binding resulting in an increase in PET from the excited QD to the receptor and a concomitant reduction in fluorescence intensity. The selectivity and sensitivity were comparable to an analogous organic dye based sensor where a similar receptor was bound to an anthracene fluorophore. Thus a modular approach is evident where a receptor used in an organic dye based sensor can be adapted and successfully used with QD's.
一种硒化镉-硫化锌量子点（QD）已采用1-(2-巯基乙基)-3-苯基硫脲进行表面功能化，其形式为光诱导电子转移（PET）型有机染料传感器典型的荧光团-间隔基-受体结构。对所得的量子点缀合物针对氟化物、氯化物、溴化物、硫酸氢盐和乙酸盐的四丁基铵盐的选择性进行了测试。添加氟离子、氯离子和乙酸根离子导致原始荧光强度大约淬灭90%，而溴离子和硫酸氢根离子几乎没有影响。观察到的淬灭归因于受体在阴离子结合后还原电位的增加，导致从激发态量子点到受体的电子转移增加，同时荧光强度降低。其选择性和灵敏度与一种类似的基于有机染料的传感器相当，在该传感器中类似的受体与蒽荧光团结合。因此，一种模块化方法很明显，即基于有机染料的传感器中使用的受体可以进行调整并成功用于量子点。
