High-performance Nanocrystal Platinum on Hierarchical Microelectrode for Biochemical Sensing

A high-performance hierarchical microelectrode array was reported, which significantly enlarged the surface area and reduced edge effect of the unevenly distributed electric field, using novel nanocrystal platinum (Pt) surface modification and hierarchical topologies. A hierarchical three-dimensional (3D) nanostructured Pt was introduced on the surface of microelectrodes (diameter Φ=10 pm, and seed pad Φ=200 μm) to reduce the impedance by ~91.2% down to 2.63 kn at 1kHz, and increase the cathodic charge storage capacity (CSCc) by ~60 times up to 217.9 mC.cm^-2 compared with that of bare Pt substrate, demonstrating superior electrochemical performances to the traditional modified electrodes. In addition, the hierarchical microelectrodes exhibited great stability and linearity for glucose sensing with a detection limit of ~1.5 μM, which showed potential applications for neural interface and biochemical sensing.