碳纳米管负载纳米金-石墨烯量子点修饰电极电化学检测过氧化氢

摘要

采用过氧化氢刻蚀法制备石墨烯量子点(GQDs),再采用原位化学还原法制备金纳米粒子-石墨烯量子点纳米复合物(AuNPs-GQDs),最后以聚二甲基二烯丙基氯化铵(PDDA)为交联剂将上述纳米复合物组装于多壁碳纳米管表面,制得金纳米粒子-石墨烯量子点-PDDA-多壁碳纳米管复合材料(AuNPs-GQDs-PDDA-MWCNTs).通过荧光光谱法、紫外-可见吸收光谱法和透射电子显微镜对上述复合材料进行表征.采用滴涂法制得该复合材料修饰的玻碳电极,研究了过氧化氢在该电极上的电化学行为.结果表明:在石墨烯量子点、金纳米粒子和多壁碳纳米管三者的协同作用下,该电极对过氧化氢的电氧化表现出强的催化活性.在优化条件下,安培法检测H2O2的线性范围为2.0×10-8~1.5×10-3 mol/L,检出限(3sb)为8.0×10-9 mol/L,灵敏度为61.6 μA/(mmol?L-1).%A glass carbon electrode was modified with gold nanoparticles(AuNPs),graphene quantum dots(GQDs) and multi-walled carbon nanotubes(MWCNTs) composite by dropping method.Firstly,GQDs were prepared using hydrogen peroxide as etching agent,then the gold nanoparticles-graphene quantum dots composite(AuNPs-GQDs) was prepared by in situ chemical reduction method and loaded on MWCNTs with poly dimethyl diallyl ammonium chloride(PDDA) as a crosslinking agent.The characterization of this composite was investigated by fluorescence spectrometry(MFS),UV-Vis absorption spectroscopy(UV-Vis spectra) and transmission electron microscopy(TEM).A glass carbon electrode modified wtih the composite(AuNPs-GQDs-PDDA-MWCNTs/GCE) was obtained with the dropping method.The electrochemical behavior of hydrogen peroxide on this modified electrode was investigated in detail.The results showed that this modified electrode had a high electrocatalytic activity for the oxidation of hydrogen peroxide under the synergic action of AuNPs,GQDs and MWCNTs.Under the optimum conditions,the linear range for the determination of hydrogen peroxide by amperometry was in the range of 2.0×10-8 - 1.5×10-3 mol/L,with a detection limit(3sb) of 8.0×10-9 mol/L and a sensitivity of 61.6 μA/(mmol?L-1).