Characterization And Application Of The Selenium Nanoparticles-biomolecules Polymerized Films

The polymer films were prepared by self assembling selenium nanoparticles(nanoSe⁰) with ascorbate acid(Vc) and selenocystine(SeCys) as affinity groups(SAM nanoSe⁰/Vc/SeCys polyfilms). The AFM and SEM showed the special 3D framework structure of the polymer films. The functions of the SAM nanoSe⁰/Vc/SeCys polyfilms on optoelectronics as fluorescence, and voltammetric characters were shown. Fluorescence spectras showed the excitation wavelength for 370nm and the emission wavelength for 470nm. Cyclic voltammograms showed a pair of redox peaks of the SAM nanoSe⁰/Vc/SeCys polyfilms at about+350mV and+200mV. The model of the special 3D framework with nanoSe⁰ and biomolecules was builted to demostrate the proceeding of assembly.Assembly of the SAM nanoSe⁰/Vc/SeCys polyfilms in liquid phase was observed by IR, UV-Vis and fluorescence. IR showed that the interaction of nanoSe⁰-Vc sol solution increased the transmission intensity of C=O=Se to demonstrate a transmission peak at 1238cm^-1. For the nanoSe⁰-Vc-SeCys sol solution, the interaction was formal the polymer to limite the vibrational and rotational ability in molecular bonds. UV-Vis showed that the strong absorption in the rage of 220-280nm is related to the enolic structure of Vc and another weak absorption in the rage of 280-350nm is related to the SeCys. The transmission intensity of C=O=Se would lead red-shifto increased the intensity of absorption in rage of 280-350nm. Fluorescence showed the excitation wavelength for 370nm and the emission wavelength for 470nm mostly related to the nanoSe⁰-Vc. The intensity of fluorescence was increased by the transmission intensity of C=O=Se in liquid phase, and by the crystallization in solid phase.Differential pulse voltammetric (DPV) determination of selenoamino acids (selenocystine (SeCys) and selenometine (SeMet)) using SAM nanoSe⁰/Vc/SeCys polyfilms modified Au electrode was presented. In PBS (pH=7.0)+0.1M NaClO₄ solution, selenoamino acids yielded a sensitive reduction peak at about +250±20mV on SAM nanoSe⁰/Vc/SeCys polyfilms modified Au electrode. The peak current had a linear relationship with the concentration of selenoamino acids in the range of 5.0×10^-8～1.0×10^-5M, and a 3σdetection limit of selenoamino acids was 1.2×10^-8M. The relative standard deviation of the reduction current at selenoamino acids concentration of 1.0×10^-6M was 5.21% when using three modified electrodes prepared at different times. The content of selenoamino acids in the selenium-enriched protein power were determined by DPV on SAM nanoSe⁰/Vc/SeCys polyfilms modified Au electrode, the content of SeCys in the selenium-enriched protein power were determined by DPV on (Se-Au)/GC electrode, respectively. VB₂, Vc, Cu (â…¡) and Ag (â… ) interfered the experiment. EDTA was used to eliminate the interference of Cu (â…¡), Ag (â… ) and the interference of VB₂, Vc was eliminated by increasing temperature. The results showed 71.5μg/g of SeCys and 65.1μg/g of SeMet in the selenium-enriched protein power. The results indicated that in selenium-enriched protein power over 60% of selenoamino acids were present as SeMet. The results of recovery in the selenium-enriched protein power were 105% of SeCys and 98.3% of SeMet.Aim to characterize the antioxidative ability of nanoSe⁰-Vc-SeCys system, used the oxygen radical absorbance capacity (ORAC) assay. The results showed that the nanoSe⁰-Vc-SeCys sol-gel solutions in different concentration had well antioxidative ability. The nanoSe⁰-Vc-SeCys sol-gel solutions were stable and had well antioxidative ability when the nanoSe⁰ under the concentration of 0.40×10^-4M. The nanoSe⁰-Vc-SeCys sol-gel solutions under high concentration, which producted SAM nanoSe⁰/Vc/SeCys polyfilms, had well antioxidative ability. These results indicated that the SAM nanoSe⁰/Vc/SeCys polyfilms had the potential ability of antioxidation.