Water-soluble multicolored fluorescent CdTe quantum dots: Synthesis and application for fingerprint developing

Multicolored water-soluble fluorescent CdTe quantum dots (QDs) have been synthesized by using Te, NaBH(4), and CdCl(2) as precursors and several mercapto-based compounds as modifiers. The effects of ratio of the precursor, type of modifier, refluxing time and initial pH value of the reaction on fluorescence intensity of CdTe QDs have been studied. XRD, HRTEM and fluorescence spectra were employed to characterize these samples. It is found that CdTe QDs with a crystalline size of 3-4 nm are homogeneously embedded in the organic matrix. The maximum fluorescence emission peaks of CdTe QDs solutions shifted from 525 nm to 591 nm according to the refluxing time. The fingerprint details on the surface of smooth objects were clearly developed with CdTe QDs solution under irradiation of UV lights. (C) 2009 Elsevier Inc. All rights reserved.