A novel nonenzymatic fluorescent sensor for glucose based on silica nanoparticles doped with europium coordination compound

Amino-functionalized luminescent silica nanoparticles (LSNPs) doped with the europium(III) mixed complex. Eu(TTA)(3)phen with 2-thenoyltrifluoroacetone (TTA) and 1.10-phenanthroline(phen) were synthesized successfully using an revised Stober method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared (FTIR), and fluorescence spectroscopy were performed for characterizing the synthesized nanoparticles. In the presence of glucose, the fluorescence intensity of the amino-functionalized LSNPs was enhanced due to the enhanced fluorescence resonance energy transfer. Based on fluorescence-enhancing effect, a simple and sensitive method for the determination of glucose was proposed. Under the optimized experimental conditions, the enhanced fluorescence intensity ratio (Delta F/F-0) was linear with the concentration of glucose (c) in the range of 0.0-180 mu g ml(-1) with a detection limit of 0.8 mu g ml(-1) (S/N = 3). The R.S.D. values were 0.33% and 0.37% at the levels of 22.5 and 100 mu g ml(-1), respectively. The proposed method was applied to the determination of glucose in synthetic samples with satisfactory results. The proposed method was also performed to the analysis of blood glucose in human serum samples and the results were in good agreement with clinical data provided by the hospital, which indicates that the method presented here is not only simple, sensitive, but also reliable and suitable for practical applications. (C) 2009 Elsevier B.V. All rights reserved.