tailieunhanh - Báo cáo hóa học: " Bioconjugates of Glucose Oxidase and Gold Nanorods Based on Electrostatic Interaction with Enhanced Thermostability"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Bioconjugates of Glucose Oxidase and Gold Nanorods Based on Electrostatic Interaction with Enhanced Thermostability | Nanoscale Res Lett 2009 4 1236-1240 DOI S11671-009-9385-8 NANO EXPRESS Bioconjugates of Glucose Oxidase and Gold Nanorods Based on Electrostatic Interaction with Enhanced Thermostability Zhanfang Ma Teng Ding Received 20 May 2009 Accepted 1 July 2009 Published online 15 July 2009 to the authors 2009 Abstract Bioconjugates made up of an enzyme and gold nanorods GNRs were fabricated by electrostatic interactions layer-by-layer method LBL between anionic glucose oxidase GOD and positively charged GNRs. The assembled processes were monitored by UV-Vis spectra zeta potential measurements and transmission electron microscopy. The enzyme activity assays of the obtained bioconjugates display a relatively enhanced thermostability behavior in contrast with that of free enzyme. Free GOD in solution only retains about 22 of its relative activity at 90 C. Unexpectedly the immobilized GOD on GNRs still retains about activity after the same treatment. This work will be of significance for the biologic enhancement using other kinds of anisotropic nanostructure and suggests a new way of enhancing enzyme thermostability using anisotropic metal nanomaterials. Keywords Gold nanorods Enzyme thermostability Glucose oxidase Polyelectrolytes Introduction Considerable effort has been devoted to the study of gold nanoparticles with variable size and shape due to their unique geometry-dependent optical electronic and catalytic properties in electronics and optics 1-5 particularly in the fields of biotechnology and nanotechnology 6-8 . Recently gold nanorods GNRs have attracted interest due to their unusual properties in electronics and optics 9 10 Z. Ma H T. Ding Department of Chemistry Capital Normal University 100048 Beijing People s Republic of China e-mail mazhanfang@ and especially in bionanotechnology fields involving bioimaging 11 12 biosensing 13-16 DNA expression 17 cancer therapy 18 etc. For GNRs two distinct plasmon bands a transverse mode 520 nm and a .