Conjugation and fluorescence quenching between bovine serum albumin and L-cysteine capped CdSe/CdS quantum dots.
Water-soluble, biological-compatible, and excellent fluorescent CdSe/CdS quantum dots (QDs) with L-cysteine as capping agent were synthesized in aqueous medium. Fluorescence (FL) spectra, absorption spectra, and transmission electron microscopy (TEM) were employed to investigate the quality of the products. The interactions between QDs and bovine serum albumin (BSA) were studied by absorption and FL titration experiments. With addition of QDs, the FL intensity of BSA was significantly quenched which can be explained by static mechanism in nature. When BSA was added to the solution of QDs, FL intensity of QDs was faintly quenched. Fluorescent imaging suggests that QDs can be designed as a probe to label the Escherchia coli (E. coli) cells. These results indicate CdSe/CdS/L-cysteine QDs can be used as a probe for labeling biological molecule and bacteria cells.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P.R. China.
Qisui
Q
Wang
Fangyun
F
Ye
Peng
P
Liu
Xinmin
X
Min
Xi
X
Li
D000818:Animals; D019187:Cadmium Compounds / Q000737:chemistry*; D002417:Cattle; D003545:Cysteine / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013194:Staining and Labeling
D019187:Cadmium Compounds; D005456:Fluorescent Dyes; D018036:Selenium Compounds; D012710:Serum Albumin, Bovine; C058667:cadmium selenide; D003545:Cysteine