Preparation of aminated core-shell fluorescent nanoparticles and their application to the synchronous fluorescence determination of gamma-globulin.
Amino-modified silica nanoparticles (FSNPs) doped with fluorescein isothiocyanate (FITC) were synthesized by using an aqueous core of reverse-micelle microemulsion as the nanoreactor in an easy one-pot method. Due to the FITC conjugating with (3-aminopropyl)triethoxysilane (APTS), the nanoparticles prevent the FITC from leaching from the silica matrix when immersed in aqueous solution. SEM, FTIR, fluorescence lifetime, a photobleaching experiment and synchronous fluorescence spectra were used to characterize the FSNPs. The synchronous fluorescence signal of FSNPs was enhanced when trace amounts of gamma-globulin (gamma-G) were added. Under the optimal experimental conditions, the enhanced fluorescence intensity (DeltaF) was linear with the concentration of gamma-G (c) in the range 0.3-4.8 microg/mL, with a detection limit of 0.04 microg/mL. The proposed method is simple, sensitive for the determination of trace amounts of gamma-G and used to determine the content of gamma-G in synthetic samples with satisfactory results.
Anhui Key Laboratory of Chemo/Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, People's Republic of China. f-gao@hotmail.com
Feng
F
Gao
Fabao
F
Luo
Jun
J
Yin
Lun
L
Wang
D016650:Fluorescein-5-isothiocyanate / Q000032:analysis / Q000737:chemistry; D005456:Fluorescent Dyes / Q000032:analysis / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D011437:Propylamines; D012680:Sensitivity and Specificity; D012821:Silanes / Q000138:chemical synthesis; D013050:Spectrometry, Fluorescence / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D005719:gamma-Globulins / Q000032:analysis*
D005456:Fluorescent Dyes; D011437:Propylamines; D012821:Silanes; D005719:gamma-Globulins; D016650:Fluorescein-5-isothiocyanate; C477625:amino-propyl-triethoxysilane