Preparation Of Silver Nanocluster-carbon Nanoparticles Hybrid Fluorescence Ratio Probe And Its Application In Detection Of Heavy Metals

In recent years,environmental pollution has become increasingly serious.As more and more heavy metal elements are used in production and life,the problem of heavy metal pollution,which is one of many environmental problems,has become increasingly prominent.Heavy metal ions such as copper ions(Cu²⁺)and lead ions(Pb²⁺)are typical heavy metal pollutants in the environment,and have a greater health hazard to organisms?especially for the human body?.Therefore,the prevention and control of heavy metal pollution in the environment has always been of concern to the public.Among them,the detection of heavy metal ions in water is one of its indispensable parts.As an important detection method for heavy metal ions in water,fluorescence analysis has been of great concern to researchers.Conventional fluorescent probes for heavy metal ion detection,such as semiconductor quantum dots,organic fluorescent dyes,and the like,are likely to cause secondary pollution to the environment,while single-signal fluorescent probes are sensitive to changes in the external environment and have poor anti-interference ability.Therefore,the development of a probe with less environmental pollution and strong anti-interference ability is of great significance for the detection of heavy metal ions in water bodies.In this thesis,a fluorescence ratio probe based on silver nanoclusters and carbon nano-dots was prepared,and the detection characteristics of heavy metal ions in water were studied.The main research content of this thesis is the preparation of silver nanocluster-carbon nanodots fluorescence ratio probes and their application in the detection of heavy metals.Firstly,silver nanoclusters and carbon nano-dots were synthesized by polymer template method and microwave method respectively.Silver nanocluster-carbon nano-dot hybridization fluorescence ratio probes were prepared by mixed hybridization method.The dilution percentage of silver nanocluster-carbon is 2.5%and the concentration of carbon nano-dot is 0.05?g/mL.Then,this dissertation studied the effect of the hybrid probes on different metal ions(Al³⁺,Fe³⁺,K⁺,Mg²⁺,Na⁺,Pb²⁺,and Cu²⁺)in water.It was found that this probe can specifically recognize copper ions and its concentration is checked for the ratio.The experimental results show that the two characteristic peaks of the silver nanocluster-carbon nano-dot hybrid fluorescence probe are located at 565 nm and 440 nm,respectively,and there are two linear intervals,when the Cu²⁺concentration is in the range of3-36?mol/L,the linear relationship between the concentration of I₅₆₅/I₄₄₀ and Cu²⁺is good,R²=0.99,the detection limit is 3?mol/L,but the linear relationship is generally in the range of 90-400?mol/L,R²=0.97.At the same time,the copper ion concentrations of three parallel spiked tap water samples were measured using the silver nanocluster-carbon nano-dot hybrid fluorescence probe method and the national standard method,respectively.The results were1.17 mg/L?RSD=7.73%?and 1.03 mg/L?RSD=2.23%?respectively,thus,the silver nanocluster-carbon nano-dot hybrid fluorescence probe method proposed in this paper has good accuracy in the detection of water-like Cu²⁺,and it's easy to use.Therefore,this paper believes that silver nanocluster-carbon nano-spot fluorescence ratio probe method has certain application potential in the field of copper ion rapid detection in water.