▎ 摘　　要

Here we report an ultrasensitive trace mercury(II) micro sensor based on heat-shrinkable polymer (polyolefins, PO). The layer-by-layer self-assembly (LBL SA) method was employed to modify mixed gold nanoparticle (Au NPs) and graphene solution on a micro gold electrode with PO substrate. The unique wrinkle structure of the electrode surface and superior properties of modification film enhanced the performance of LBL SA graphene-Au NPs shrink sensor greatly in determination of Hg(II) using anodic stripping voltammetry (ASV): compared with a shrink gold electrode without surface modification, the sensitivity was improved for about 3.7 times from 0.197 to 0.721A/ppb; compared with a same-sized sensor without surface modification nor shrink, the sensitivity was improved for over 50 times. This sensor's detection limit of Hg(II) was achieved as 0.931ppb with a sensitivity of 0.721A/ppb. This simple but highly sensitive sensor can be widely used in applications of on-line environmental monitoring of Hg(II).