Synchronous fluorescence determination of protein with functionalized CdS nanoparticles as a fluorescence probe

Nanometer-sized fluorescent particles have been successfully synthesized. A synchronous fluorescence method, with high sensitivity and selectivity, has been developed for rapid determination of protein with functionalized CdS as a fluorescence probe. When Deltalambda = 260 nm, maximum synchronous fluorescence is produced at 274 nm at pH 7.0. Under optimal conditions, the calibration graphs are linear over the range 0.1-3.0 mug ml(-1) for bovine serum albumin (BSA), 0.1-11.0 mug ml(-1) for gamma-globulin (gamma-G) and 0.1-4.4 mug ml(-1) for human serum albumin (HSA), respectively. Limits of determination were 0.01 mug ml(-1) for BSA, 0.019 mug ml(-1) for mu-G and 0.021 mug ml(-1) for HSA, respectively. The relative standard deviations of seven replicate measurements were 1.8% for 1.0 mug ml(-1) BSA, 2.2% for 1.0 mug ml(-1) gamma-G and 2.3% for 1.0 mug ml(-1) HSA. (C) 2002 Elsevier Science B.V. All rights reserved.