Rational Assembly Of Superstructure Microparticles Into Mosaic-Like Highly Oriented Monolayer For Glucose-Responsive Electrodes

Assembly of functional superstructure microparticles into large-scale transferable ensembles is a practical approach to elaborate collective properties for catalytic and sensing applications. Here, a two-step assembly process is proposed to fabricate a mosaic-like highly oriented monolayer consisting of densely packed CuI superstructure microparticles (s-CuI) over a large area. First, optimized synthesis and Cl doping of rectangular sheet-like s-CuI is achieved by antisolvent crystallization. Then, a steep capillary gradient is created along the water surface to compress the pre-dispersed s-CuI into a centimeter-sized mosaic-like highly oriented monolayer, which can be integrally transferred onto fluorine-doped tin oxide glass substrates. The s-CuI monolayer with optimal Cl doping exhibits a highly sensitive electrochemical response to glucose in a nonenzymatic weakly alkaline environment. A photoelectrochemical response to glucose can also be achieved in nonenzymatic neutral solution. The high performances are ascribed to large surface area, excellent electrical contact, and consistently exposed Cu+ active sites of the s-CuI building blocks.