Study On Synthesis And Analytical Application Of Functionalized Template Stabilized Gold And Copper Nanoclusters

Fluorescent noble metal nanoclusters(NMNCs)a kind of ultra-small nanoparticle(less than 2nm)protected in special stabilizers.The fluorescence emission wavelength of noble metal nanoclusters is closely related to the number of metal atoms in the core.Due to its ultra-small size,noble metal nanoclusters have discrete electronic structures and molecular-like properties such as HOMO-LUMO electron transfer,photoluminescence enhancement,intrinsic magnetism,et.al.Fluorescent noble metal nanoclusters,especially gold nanoclusters(Au NCs)and cooper nanoclusters(Cu NCs)were proposed as novel optical sensors for environmental monitoring due to their fluorescence stability,biocompatibility and wide emission spectrum ranges.They have become a promising material due to their fascinating performance,such as being eco-friendly and having high colloidal stability,superior catalytic activity,unusual photophysical properties,and good biocompatibility,which facilitates applications in bioimaging,catalysis,biochemical sensing,environmental monitoring and the detection of heavy metal ions,inorganic anions.In this thesis,the synthesis methods and analytical applications of gold nanoclusters and copper nanoclusters are studied,the details are as follows:1.A new type of fluorescence gold nanoclusters with emitting green fluorescence was synthesized using SH-?-cyclodextrin as a template(AuNCs@6-SH-CD).Different from red-emission fluorescent gold nanoclusters,the AuNCs@6-SH-CD has a maximum emission wavelength of 502 nm and a half-width of about 50 nm.The green-color emission Au NCs exhibit a simple and efficient strategy to detect p-nitrophenol(PNP).The recognizing of PNP has higher selectivity to o-nitrophenol and m-nitrophenol.The linear range for PNP detection is 0.10-100.0?M and the detection limit is 0.087 ?M2.A new type of fluorescence gold nanoclusters with stable fluorescence emission located around 600 nm was synthesized by using photo-reducing method under ultraviolet light.Different from common synthesis method,the synthesis of the new SH-?-CD stabilized gold nanoclusters could be finished in 90 min.Under ultraviolet light illumination,silver nanoparticles that formed by silver ions are an excellent catalyzer that could quickly catalyze the growth of gold nanoclusters.The presence of Ag+ in gold nanoclusters synthesis could effectively change the fluorescence intensity and peak position of the nanoclusters.Silver ions in the concentration range from 22.0-400.0 ?M can be linearly detected.3.A new type of copper nanoclusters was synthesized by chemical reduction at a high temperature of 85 ? without the addition of an additional reducing agent.The 6-SH-CD was used as both a stabilizer and a reducing agent to produce fluorescence copper nanoclusters,and the as-prepared copper nanoclusters have bright fluorescence emission located at 475 nm.The copper nanocluster also has better stability that common copper nanoclusters.4.A new type of copper nanoclusters was synthesized using copper nitrate as a precursor,ascorbic acid as a stabilizer and histidine as a ligand.A copper-ascorbic acid complex was first synthesized,and the L-histidine was added to the complex for ligand exchange reaction with ascorbic acid.Then,blue-green fluorescent copper nanoclusters(CuNCs@His)produced after the ligand exchange reaction have bright fluorescence emission located at 480 nm and better stability.