Soft Microelectrode Linear Array for Scanning Electrochemical Microscopy

摘要

A linear array of eight individual addressable microelectrodesnhas been developed in order to perform highthroughputnscanning electrochemical microscopy (SECM)nimaging of large sample areas in contact regime. Similarnto previous reports, the soft microelectrode array wasnfabricated by ablating microchannels on a polyethylenenterephthalate (PET) film and filling them with carbon ink.nImprovements have been achieved by using a 5 μm thicknParylene coating that allows for smaller working distances,nas the probe was mounted with the Parylene coating facingnthe sample surface. Additionally, the application of anSECM holder allows scanning in contact regime with antilted probe, reducing the topographic effects and assuringnthe probe bending direction. The main advantage of thensoft microelectrode array is the considerable decrease innthe experimental time needed for imaging large samplenareas. Additionally, soft microelectrode arrays are verynstable and can be used several times, since the electrodensurface can be regenerated by blade cutting. Cyclic voltammogramsnand approach curves were recorded in ordernto assess the electrochemical properties of the device. AnnSECM image of a gold on glass chip was obtained withnhigh resolution and sensitivity, proving the feasibility ofnsoft microelectrode arrays to detect localized surfacenactivity. Finite element method (FEM) simulations werenperformed in order to establish the effect of diffusion layernoverlapping between neighboring electrodes on the respectivenapproach curves.