Studies On Spectral Properties Of Gold, Silver And Platinum Coordination Nanoparticle Systems And Their Analytical Application

Analytical Application Because nanoparticles (qutantum dots) lie in the exchanging band of clusters and macroscopic substances and their sizes are between 0.1 nm and 100 nm,they have surface,volume,quantum size and macroscopic quantum tunnel effects,which result in many strange properties of mechanics,electricity,heat,optics and chemistry and so on.This introduction summarizes the research progress of nanoparticle spectral properties,namely, the absorption, fluorescence and resonance scattering spectra,and their analytical application to trace metal ions and proteins is expounded. Part Two. Interface Fluorescence and Resonance Scattering Spectral Properties of AgX Nanoparticles in Liquid Phase The resonance scattering and emission spectra of AgX(X=Cl,Br and I) nanoparticles in liquid phase show that AgCl and AgBr nanoparticles all exhibit four resonance scattering peaks at 330, 400, 470 and 680nm, three fluorescence peaks at 340, 400 and 470nm.While AgI nanoparticles produce five resonance scattering peaks at 340, 400, 437, 470 and 680nm, it has a strongest fluorescence peaks at 434nm and three other peaks at 340, 400 and 470nm. The concentration of the system of AgX nanoparticles influence on the resonance scattering signals is consistent with that on the fluorescence intensities. And the resonance scattering intensity of AgCl, AgBr and AgI system is 110, 130 and 80 times of the fluorescence intensity, respectively. That is, there is the correlation between the fluorescence and resonance scattering. The fluorescence mechanism of AgX nanoparticles has been proposed, the reason that there is the correlation between the fluorescence and resonance scattering has been explained. Part Three. The Spectral Properties Study of Ag(I)-DDTC Chelate Complex Nanoparticles and Its Analytical Application In pH 10.5 NH3-NH4Cl buffer solution and in the presence of zephiran chloride surfactant, Ag (I)and sodium diethyldithiocarbamate (DDTC) form complex molecule, which can self-aggregate to stable colorless (Ag-DDTC)n chelate complex nanoparticles. It exhibits a resonance scattering (RS) peak at 361 nm and a synchronous scattering peak at 464 nm. There are two fluorescence peaks at 400 and 466 nm when the excited wavelength is 260 nm. The RS intensity at 361 nm and fluorescence at 400 nm with Ag (I)concentration show good linearity over the concentration range 0.043～3.24μg/mL. A new resonance scattering method for determination of Ag using DDTC is founded, with a detection limit of 0.010μg/mL. The method is used to determinate the trace silver in photograph and waste water, with satisfactory results. Part Four. Resonance Scattering and Fluorescence Spectral Study of the Nanoparticle System of AuCl4--I- AuCl4-reacts with I-to form AuI nanoparticles in size of 12 nm. When the concentration of I-is lower, the system is in light yellow of AuCl4-molecules. It exhibits a strong and wide resonance scattering peak at about 320 nm, and a synchronous scattering peak at 470nm, and four fluorescence peaks at 350nm, 400nm, 420n and 466nm. When the concentration is higher, the nanoparticle system is in yellow-green. It exhibits three resonance scattering peaks at 360nm, 420nm and 520nm, and a synchronous scattering peak at 470nm, and a strong fluorescence peaks at 466nm. The influence of the concentration of AuI nanoparticles on the resonance scattering signal and fluorescence intensity is consistent. The nano-reaction mechanism of AuI has been investigated adopting spectroscopy, polarography and transmission electron microscopy. In addtion to I2, there are (AuI)n nanoparticle and IO3-in the system. And a new analytical reagent of AuI2-in resonance scattering spectral analysis has been prepared. Part Five. The Spectral Properties Study of AuCl4--X--ADR Nanoparticles and Its Analytical Application In pH 3.6 Walpole buffer solution, acridine red (ADR) has a absorption peak at 526nm and a fluorescence peak at 570nm. AuCl4-and excess I-react to form AuI2-and I3-, then they associate with ADR to (2ADR-AuI2-I3)n association particles which produce three resonance scattering peaks at 320, 400 and 600 nm and exist fluorescence quenching at 570nm and hyprochromic effect at 526nm. The concentration of Au (Ⅲ) and resonance scattering intensity ΔI600 nm show linearity in the range of 0.047～2.84 μg/mL with a detection limit of 0.011 μg/mL. The method is used to determine gold in waste water, with satisfactory results. Part Six. The Spectral Properties of PtCl2--I--Protein Associated Particle Systems and Its Application to Resonance Scattering Spectral Analysis In Walpole buffer solution of suitable pH value and in the presence of surfactant Triton X-10, PtCl62-react with I-to form PtI62-. Acted on the electrostatic and hydrophobic forces, proteins with positive charge, such as human serum albumin (HSA), bovine serum albumin (BSA), human immunoglobulin (IgG) and ovalbumin (OVA), associate with PtI62-to form stable [protein-(PtI6)n]m association particles which cause substantial enhancement of synchronous scattering and interface fluorescence. They produce three synchronous scattering peaks at 330, 420 and 464 nm and a resonance scattering one at 580 nm, among which is the strongest one at 464 nm. The four kinds of protein association particle system all create a strong fluorescence peak at 466 nm, while the one of HSA at 360 nm quenchs with the increase of association particle concentration. The cause of the synchronous scattering peaks of the association particle system is explained, and the relation between the synchronous scattering and fluorescence of the association particle and the fluorescence of HSA is interpreted. Under the optimal experimental conditions, there is a good linear relationship between the protein concentration in the range of 0.1~25μg/mL for HSA, 0.1~25μg/mL for BSA, 0.6~30μg/mL for IgG and 0.2~16μg/mL for OVA respectively and resonance scattering intensity (I464 nm) with the dection limit of 72.6 ng/mL for HSA, 79.1ng/mL for BSA, 61.0 ng/mL for IgG and 141.0 ng/mL for OVA respectively. This assay is applied to the determination of the albumin of human serum samples with satisfactory results.