适配体介导纳米银催化共振瑞利散射法测定水中痕量钾离子

Aptamer Mediated Nanosilver Catalytic Resonance Rayleigh Scattering Method for Determination of Trace Potassium Ion in Water

在钾适配体(ssDNA)探针存在时,ssDNA吸附在纳米银表面,导致纳米银的催化作用弱,而当溶液中存在钾离子时,形成钾离子-ssDNA复合物,使ssDNA从纳米银表面脱附,此时纳米银得到释放,从而纳米银催化作用增强。随着钾离子浓度的增加,脱附的银纳米粒子越多,催化H_2O_2还原HAuCl_4反应加快,随着钾离子加入量的增大,催化反应速率随之显著增强,生成的金纳米溶胶具有较高的共振瑞利散射(RRS)效应,导致体系在300nm处的RRS强度线性增强。钾离子浓度在0~1.5μmol·L^(-1)范围内,于300nm处的RRS强度增强值ΔI呈良好的线性关系。据此,可建立一种间接检测钾离子的RRS方法。

Potassium adapter（ssDNA）adsorption on the surface of nanosilver,that lead to weak the catalysis.When the presence of potassium ions,the formation of K-ssDNA complexes,ssDNA from stripping on the surface of silver nanoparticles,nanosilver release right now,catalysis increase.With the increase of K+concentration,the more silver nanoparticles stripping,H2 O2 catalyzed reduction of HAuCl4 reaction is accelerated,with the increase of potassium ion,catalytic reaction rate significantly enhanced the generated gold nanoparticle sol has higher RRS effect,lead to system of Rayleigh scattering intensity at 300 nm increase linearly.Potassium ion linear concentration is 01.5μmol·L-1.Accordingly,a RRS method for potassium was established.