ABSTRACT
Gold nanorods is a capsule-shaped gold nanoparticles. Gold nanorods give rise to two absorption peaks corresponding to their plasmonic modes, transverse mode and longitudinal mode, corresponding to light absorption and scattering along the short and long axis, respectively. The longitudinal surface plasmon resonance can be tuned by adjusting their aspect ratio from the visible to the NIR region and extremely sensitive to changes in the dielectric properties of the surroundings including solvents, adsorbates, and the interparticle distance of the gold nanorods. This unique optical property of gold nanorods opens up fascinating applications in biological and chemical sensors. Optical properties and biomedical application of gold nanorods are introduced, and its future research prospects are discussed.
ABSTRACT
Objective To study the interaction between Cr(Ⅵ)-GSH complex and DNA and to understand the mechanism of DNA conformation change induced by Cr(Ⅵ)-GSH complex. Methods Chromium(Ⅵ) reacts on glutathione forms the chromium (Ⅴ) intermediate complex, and the intermediate complex can induce the conformation change of DNA, in the present paper, ultraviolet and fluorescence spectra, Scatchard equation, fluorescence quenching curve, and fluorescence probe method using ethidium bromide (EB) as a fluorescence probe were employed. Results The chromium (Ⅴ) intermediate complex formed rapidly after the reaction between Cr(Ⅵ) and GSH in Hepes buffer solution at pH=7.4, the complex did not insert into the base pairs on the DNA duplex strand and developed electrostatic binding with the phosphate backbone of DNA, but induced a conformation change of DNA leading to a disruption of duplex structure. In the following time, the complex decomposed and the end product was Cr(Ⅲ), Cr(Ⅲ) can cross-link with DNA, the whole process needs about an hour. Conclusion The chromium(Ⅴ) intermediate complex of the conformation change reaction of chromium(Ⅵ) and glutathione may play an important role in inducing the DNA.
ABSTRACT
Objective To study the effects of surfactants on conformation of hemoglobin and further to understand the potential impact of surfactants in environment on human health. Methods The changes of the conformation of hemoglobin induced by cation and anion surfactants were investigated with four methods, such as synchronous fluorescence spectra, UV, electrochemistry and atom force microscope. Results The changes of the conformation of hemoglobin induced by anion surfactant were obvious but were not by cation surfactant. Conclusion Sodium lauryl sulphate, an anion surfactant, may change the conformation of hemoglobin.