配体调控GONR催化H_2O_2还原HAuCl_4-RRS法测定Ni^(2+)

A Novel RRS Method for Trace Ni^(2+) by Dimethylglyoxime Reaction Regulating Graphene Oxide Nanoribbon

在60℃水浴条件下,过氧化氢(H_2O_2)还原HAuCl_4生成金纳米溶胶反应缓慢,加入氧化石墨烯纳米带(GONR)等纳米酶催化剂后,反应加快。当有丁二酮肟(DMG)配体存在时,DMG吸附在GONRs表面,导致GONR的催化作用减弱;而当溶液中存在Ni^(2+)时,形成Ni(DMG)2复合物,使DMG从GONRs表面脱附,此时GONRs得到释放,使得从而GONRs催化效应活化,催化作用增强。随着Ni^(2+)浓度的增加,脱附的GONRs越多,催化H_2O_2-HAuCl_4反应加快,体系生成的金纳米粒子增多,体系的RRS信号增强,当Ni^(2+)浓度在0.07~0.98μmol·L^(-1)浓度范围内,ΔI_(540nm)与Ni^(2+)浓度呈良好的线性关系,线性方程为ΔI_(540nm)=729.31c+32.049,线性相关系数R^2=0.991 4,检测限为0.028μmol·L^(-1)。

The nanogold reaction between HAuCl4 and H2 O2 was very slow under 60℃ water bath,and the as-prepared graphene oxide nanoribbons（GONRs）catalyst exhibited strong catalysis on the reaction to form gold nanoparticles（AuNPs）that appeared a strong Resonance Rayleigh scattering（RRS）peak at 540 nm.With the increase of the amount of GONRs,the RRS peak enhanced due to the GONR nanocatalysis increasing.Upon addition of dimethylglyoxime（DMG）ligand,it adsorbed on GONRs surface to inhibite the catalysis of GONRs that cause the RRS peak decreased.Moreover,the coordination reaction between DMG and Ni2+take place to form a stable complexes of[Ni（DMG）2]2+and release free GONRs catalyst that results in the RRS peak increasing with Ni2+concentration.Accordingly,a RRS quantitative analysis method for Ni2+was established,with a linear range of 0.070.98μmol·L-1,and a detection limit of 0.028μmol·L-1 Ni2+.