Shrink-Induced Microelectrode Arrays for Trace Mercury Ions Detection

An ultrasensitive microelectrode arrays (MEA) mercury sensor based on the heat-shrinkable polymer was fabricated by a very simple and low-cost method for the first time. We sputter a comb-finger gold electrode on the heat-shrinkable polymer, made use of the heat shrinkage and sticky characteristics of the polymer to construct MEA, and then detected the trace mercury ions (Hg2+) in the water by anodic stripping voltammetry. The characterization result indicated that the shrink polymer prepared by different heating temperature had controllable shrinkage ratios, and the electrode surface presented unique wrinkle structure by heating process. Due to the non-linear diffusion characteristic of the microelectrode and the microwrinkle structure, performance of the sensor had been improved greatly. The signal-to-noise ratio (Faraday current divide Background current) increased notably, and the sensor's detection limit was achieved as 0.0874 ppb. This is a very effective way to detect ultra-low concentrations mercury ions and the heat-shrinkable film-based microelectrode arrays construction method can be applied to many fields.