Abstract:

Water-soluble fluorescent CdSe quantum dots(QDs) were synthesized using thiolglycolic acid(TGA) as the stabilizer and characterized by fluorescence spectroscopy. The material exhibited strong visible fluorescence under excitation at 365 nm. QDs were applied to label blood fingerprints deposited on non-porous surfaces. Then fluorescent images of fingerprints were obtained by the charge-coupled device(CCD) camera. The effects of labeling time，blood concentration and stored time of blood fingerprints to imaging were investigated. The results showed that the fluorescent images could be obtained within labeling time of 30 min. CdSe QDs can detect blood fingerprints on different surfaces especially on black surface; 1% diluted blood fingerprints also could be labeled. The labeled blood fingerprints have higher and stable fluorescence intensity, weaker background interference and better contrast between fingerprints and substrate. CdSe QDs are promising reagents for blood fingerprints development on non-porous dark surfaces.

Key words: CdSe quantum dots, blood fingerprints, labeling, fluorescent-based imaging