A rapid, ultrasensitive and convenient fluorescence measurement technology based on the enhancement of the fluorescence intensity resulting from the interaction of functionalized CdSe/CdS quantum dots （QDs） with bov...A rapid, ultrasensitive and convenient fluorescence measurement technology based on the enhancement of the fluorescence intensity resulting from the interaction of functionalized CdSe/CdS quantum dots （QDs） with bov/ne serum albumin （BSA） was proposed. The citrate-stabilized CdSe/CdS （QDs） were synthesized by using Se powder and Na2S as precursors instead of any pyrophoric organometallic precursors. The modified CdSe/CdS QDs are brighter and more stable against photobleaching in comparison with organic fluorophores. At pH 7.0, the fluorescence signal of CdSe/CdS is enhanced by increasing the concentration of BSA in the range of 0.1-10 μg/mL, and the low detection limit is 0.06 μg/mL. A linear relationship between the enhanced fluorescence peak intensity （△F） and BSA concentration （c） is established using equation △F=50.7c＋16.4 （R=0.996 36）. Results of determination for BSA in three synthetic samples are identical with the true values, and the recovery （98.9%-102.4%） and relative standard deviation （RSD, 1.8%-2.5%） are satisfactory.展开更多
The formation of self assembled CdSe quantum dots under Stranski Krastanow (S K) mode by low pressure metalorganic chemical vapor deposition (LP MOCVD) was reported for the first time. The samples were grown directly ...The formation of self assembled CdSe quantum dots under Stranski Krastanow (S K) mode by low pressure metalorganic chemical vapor deposition (LP MOCVD) was reported for the first time. The samples were grown directly on GaAs (100) surfaces by LP MOCVD. DimethylSelenide (DMSe) and DimethylCadmium (DMCd) were used as precursors. The growth pressure was kept at 2 93×10 4Pa and the growth temperature was 500℃. CdSe with the thickness of about 2 monolayers was grown directly on GaAs (100) surfaces. For the purpose of AFM observation, this uncapped sample was cooled down immediately to room temperature and was monitored under a Digital Instruments Nanoscope Ⅲa system at the same day of growth. The AFM images show that the average diameter, height and density of those self assembled CdSe quantum dots are 50±15nm, 13±4nm and 5μm -2 , respectively. And those dots’ diameter height ratio is about 4～5, just the same as those results observed in other Ⅱ Ⅵ and Ⅲ Ⅵ compounds which were grown under S K mode by MBE.展开更多
基金Project(50772133) supported by the National Natural Science Foundation of China
文摘A rapid, ultrasensitive and convenient fluorescence measurement technology based on the enhancement of the fluorescence intensity resulting from the interaction of functionalized CdSe/CdS quantum dots （QDs） with bov/ne serum albumin （BSA） was proposed. The citrate-stabilized CdSe/CdS （QDs） were synthesized by using Se powder and Na2S as precursors instead of any pyrophoric organometallic precursors. The modified CdSe/CdS QDs are brighter and more stable against photobleaching in comparison with organic fluorophores. At pH 7.0, the fluorescence signal of CdSe/CdS is enhanced by increasing the concentration of BSA in the range of 0.1-10 μg/mL, and the low detection limit is 0.06 μg/mL. A linear relationship between the enhanced fluorescence peak intensity （△F） and BSA concentration （c） is established using equation △F=50.7c＋16.4 （R=0.996 36）. Results of determination for BSA in three synthetic samples are identical with the true values, and the recovery （98.9%-102.4%） and relative standard deviation （RSD, 1.8%-2.5%） are satisfactory.
文摘The formation of self assembled CdSe quantum dots under Stranski Krastanow (S K) mode by low pressure metalorganic chemical vapor deposition (LP MOCVD) was reported for the first time. The samples were grown directly on GaAs (100) surfaces by LP MOCVD. DimethylSelenide (DMSe) and DimethylCadmium (DMCd) were used as precursors. The growth pressure was kept at 2 93×10 4Pa and the growth temperature was 500℃. CdSe with the thickness of about 2 monolayers was grown directly on GaAs (100) surfaces. For the purpose of AFM observation, this uncapped sample was cooled down immediately to room temperature and was monitored under a Digital Instruments Nanoscope Ⅲa system at the same day of growth. The AFM images show that the average diameter, height and density of those self assembled CdSe quantum dots are 50±15nm, 13±4nm and 5μm -2 , respectively. And those dots’ diameter height ratio is about 4～5, just the same as those results observed in other Ⅱ Ⅵ and Ⅲ Ⅵ compounds which were grown under S K mode by MBE.
