Adsorption,Immobilization And Self-assembly Of Noble Metal Nanoparticles Based On Boronate Affinity

Noble metal nanoparticles?NMNPs?have been used in electronics,biology,chemistry and medicine.At the same time,with the wide application of NMNPs,their content in the environment reaches the upper limit of threat to the ecosystem.Therefore,there is an urgent need for a viable separation method to solve this problem.After separation and enrichment of NMNPs,they can be reused in the fields of catalysis,sensing and medicine.Therefore,firstly,this paper combined the magnetic solid phase extraction method with magnetic boronic acid adsorbent to adsorb and immobilize AuNPs and AgNPs in the water.Then the cis-diol compounds were detected by the self-assembly of AuNPs based on boronate affinity.The research content includes:1.The boronic acid group has a boronate affinity with the?-hydroxycarboxylic acid on the surface of AuNPs and AgNPs.Therefore,the magnetic nano-adsorbent containing boronic acid groups was prepared and combined with magnetic solid phase extraction to remove AuNPs and AgNPs in the water.Under the optimal adsorption conditions,the recovery rates of AuNPs and AgNPs are 77.1-89.5%and 81.1-105.6%,the adsorption capacity are828.6 mg/g and 209.1 mg/g,respectively.This method still has a good adsorption effect on the aggregated NMNPs.The adsorbed AuNPs and AgNPs can be reused in immobilized form.The catalytic activity of AuNPs and AgNPs after immobilization is used as a catalyst that it is easy to recover and stabilize.2.Firstly,the self-assembly of AuNPs was induced by the boronate affinity of4,4?-biphenyldiboronic acid with?-hydroxycarboxylic acid on the surface of AuNPs.When dopamine was added to the above experimental process can inhibit the self-assembly of AuNPs.Therefor,the analytical method was established for dopamine.Next,the analytic conditions for dopamine were optimized.And glucose,fructose and tyrosinase were tested under optimal experimental conditions.The results show that the linear range for dopamine is between 0.01-10?M.By plotting the relationship between Ex_{521 nm}/Ex_633nmand concentration,there is a good linear relationship between the cis-diol compounds in certain concentration range.The detection concentration of tyrosinase is in a good linear relationship in the range of 8-36 U/mL?correlation coefficient R²=0.9988?.It is indicated that the method has utility for the detection of substances such as dopamine,glucose,fructose and tyrosinase.