Li, M (reprint author), Qilu Univ Technol, Sch Mat Sci & Engn, 3501 Daxue Rd, Jinan 250353, Shandong, Peoples R China.
; Wang, B (reprint author), Chinese Acad Sci, Inst High Energy Phys, Lab Biomed Effects Nanomat & Nanosafety, 19B Yu Quan Rd, Beijing 100049, Peoples R China.
文章类型:
期刊论文
英文摘要:
Direct and real-time measurement of nitric oxide (NO) in biological media is very difficult due to its transient nature. Fe3O4 nanoparticles (nanoFe(3)O(4)) because of their unique catalytic activities have attracted much attention as catalysts in a variety of organic and inorganic reactions. In this work, we have developed a magnetic Fe3O4 nanoparticle-based rapid-capture system for real-time detection of cellular NO. The basic principle is that the nanoFe(3)O(4) can catalyze the decomposition of H2O2 in the system to generate superoxide anion (O-2 (center dot-)) and the O-2 (center dot-) can serve as an effective NO center dot trapping agent yielding peroxynitrite oxide anion, ONOO-. Then the concentration of NO in cells can be facilely determined via peroxynitrite-induced luminol chemiluminescence. The linear range of the method is from 10(-4) to 10(-8) mol/L, and the detection of limit (3 sigma, n = 11) is as low as 3.16 x 10(-9) mol/L. By using this method, the NO concentration in 0.1 and 0.5 mg/L LPS-stimulated BV2 cells was measured as 4.9 and 11.3 mu M, respectively. Surface measurements by synchrotron X-ray photoelectron spectroscopy (SRXPS) and scanning transmission X-ray microscopy (STXM) demonstrate the catalytic mechanism of the nanoFe(3)O(4)-based system is that the significantly excess Fe(II) exists on the surface of nanoFe(3)O(4) and mediates the rapid heterogeneous electron transfer, thus presenting a new Fe2O3 phase on the surface.
