Ag shell thickness control method of Au@Ag nano core-shell material and application thereof

Abstract

The invention relates to an Ag shell thickness control method of an Au@Ag nano core-shell material and application thereof. Ag<+> in a silver nitrate solution is reduced through ascorbic acid, meanwhile, the reduction rate of the Ag<+> is slowed down in a step-by-step dropwise adding and ammonia water complexing mode, and the adding amount of the Ag<+> can be calculated through a relation formula between the silver nitrate solution and the particle size of a nano gold core and the particle size of the Au@Ag nano core-shell material; a series of Au@Ag NPs with controllable Ag shell thickness are synthesized by controlling the volume of the added silver nitrate solution, the control method is easy to repeat and low in cost, the Au@Ag nano core-shell material with uniform particle size and Ag shell thickness can be synthesized, and the effect is good. The intensity of the Au core electron compensation effect is changed by controlling the thickness of the Ag shell, and then the Ag shell thickness suitable for being applied to the biomedicine field and the biological tracking field is obtained.

Description

technical field [0001] The invention relates to the field of environmental material research, in particular to a method for controlling the Ag shell thickness of an Au@Ag nano core-shell material and its application. Background technique [0002] Silver nanoparticles (Ag NPs) have attracted worldwide attention due to their unique optical, catalytic, sensing and antibacterial properties. The plasmon resonance effect of Ag NPs makes them have broad application prospects in biosensing, surface-enhanced Raman scattering spectroscopy, plasmonic nanolaser technology, and solar energy harvesting. However, due to the poor chemical stability and biocompatibility of Ag NPs, they are easily oxidized, which will reduce the plasma performance and promote the release of silver ions (Agion, Ag+), which may cause greater biological toxicity. However, Ag NPs are widely used in various commercial products, including mobile phones, toothbrushes, cosmetics, textiles, etc., due to their excelle...

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Problems solved by technology

Moreover, Au core-labeled Ag NPs can distinguish between granular and ionic Ag using conventional metal analysis instruments. At the same time, compared with external labels such as fluorescent labels, the Au label inside the nanomaterial will not change the properties of Ag NPs. On the surface, Au core labeling technology is a very promising biotracking technology, but there is still a lack of systematic research on whether Au@Ag NPs can replace Ag NPs for biotracking, and whether Au cores will affect the bioaccumulation and toxicity of Ag NPs. Research

Moreover, from previous studies, an electron compensation phenomenon from Au to Ag was found in Au-Ag nanostructures (such as Au-Ag core-shell structures and alloys), which is beneficial for electron enrichment on the Ag side and preventing Ag oxidation. , and then reduce the release of Ag+. However, when the nano-Au core particle size is constant, increasing the thickness of the Ag shell will weaken the electronic compensation effect, making the application of Au-Ag nanostructures in vivo no longer safe.

Since the Ag shell thickness of Au@Ag core-shell nanomaterials cannot be quantitatively controlled, its impact on bioaccumulation and biotoxicity cannot be effectively evaluated, which seriously affects the application range of Au@Ag core-shell nanomaterials.

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