An ultrasensitive mercury sensor based on self-assembled graphene and gold nanoparticles on shrink polymer

Ultrasensitive trace mercury (II) micro sensor fabricated by mixed gold nanoparticle (Au NPs) and graphene suspension solution, and layer-by-layer self-assembled (LBL SA) on a shrink polymer based micro gold electrode is reported for the first time. Owing to the unique wrinkle surface structure and superior properties of modification film, performance of the LBL SA Graphene-Au NPs shrink sensor has enhanced greatly in determination of Hg (II) using anodic stripping voltammetry (ASV): compared with a shrink gold electrode without surface modification, the sensitivity is improved for about 3.7 times from 0.197 μA/ppb to 0.721 μA/ppb; compared with a same-sized sensor without surface modification nor shrink, the sensitivity is improved for over 50 times. This sensor`s detection limit of Hg (II) achieved 0.931 ppb with a sensitivity of 0.721 μA/ppb. This simple but highly sensitive sensor can be widely used in applications of on-line environmental monitoring of Hg (II).