Stripping Voltammetric Detection of Mercury(II) Based on a Bimetallic Au−Pt Inorganic−Organic Hybrid Nanocomposite Modified Glassy Carbon Electrode

摘要

A new, highly sensitive and selective sensor for thenelectrochemical assay of Hg(II) by anodic stripping vol-ntammetry has been developed, whereby a glassy carbonnelectrode is modified with a novel inorganic organicnhybrid nanocomposite, namely, bimetallic Au Pt nano-nparticles/organic nanofibers (labeled as Au PtNPs/NFs).nThe sensor possesses a three-dimensional (3D) porousnnetwork nanoarchitecture, in which the bimetallic Au PtnNPs serving as metal NP-based microelectrode ensemblesnare homogenously distributed in the matrix of interlacednorganic NFs. The surface structure and composition ofnthe sensor were characterized by scanning electron mi-ncroscopy (SEM) and X-ray photoelectron spectroscopyn(XPS). Its electrochemical performance was systematicallyninvestigated. Our results show that such a newly designed,nAu PtNPs/NF nanohybrid modified electrode providesnremarkably improved sensitivity and selectivity for thenstripping assay of Hg(II). The detection limit is found tonbe as low as 0.008 ppb (S/N 3) that is much below thenguideline value from the World Health Organizationn(WHO). Interferences from other heavy metal ions suchnas Cu(II), Cr(III), Co(II), Fe(II), Zn(II), and Mn(II) ionsnassociated with mercury analysis are effectively inhibited.nToward the goal for practical applications, the sensor wasnfurther evaluated by monitoring Hg(II) in tap and rivernwater specimens.