【摘要】 在70℃水浴条件下,柠檬酸三钠（TCA）还原HAuCl₄反应进行缓慢,加入石墨烯量子点（GQDs）作催化剂,反应加快。增大GQDs的加入量,反应随之显著增强,体系中生成的金纳米粒子增多,产生较高的共振瑞利散射（RRS）强度。在加入BaCl₂配体后,GQDs表面被BaCl₂包裹,抑制了GQDs的催化作用;当溶液中硫酸根离子(SO₄^2-)存在时,生成BaSO₄沉淀,GQDs从BaCl₂表面脱离,此时GQDs恢复其催化作用,并随着SO₄^2-浓度的增加,GQDs的脱附量增多,体系的反应速度加快,催化反应随之增强,RRS信号线性增强。信号增强值与SO₄^2-在0.067～1.67μmol·L^-1范围内呈良好线性关系,检测限为0.041μmol·L^-1,线性方程为ΔI_570nm=93.3c+0.4。更多还原

【Abstract】 In a 70℃ water bath,the reaction of trisodium citrate（TCA）-HAuCl₄ is slow.Graphene quantum dots（GQDs）was used as catalysts to accelerate the reaction.With the increase of the GQDs,the reaction increases remarkably to produce gold nanoparticles,which resulting in higher resonance Rayleigh scattering（RRS）intensity.The GQDs surface was encapsulated when BaCl₂ was added and the catalysis of GQDs reduced.There BaSO₄ is precipitates and GQDs were detached from the surface of BaCl₂ when sulfate ions(SO₄^2-)existed in the solution.At this time,GQDs recovered its catalysis with the SO₄^2- increase,and the reaction speed.The signal of RRS increased linearly,and the signal enhancement value showed a good linear relationship with SO₄^2- in the range of 0.067～1.67μmol·L^-1,with a detection limit of 0.041μmol·L^-1 and the linear equation of ΔI_{570 nm}=93.3 c+0.4.更多还原