Assembling Metal–Organic Frameworks into the Fractal Scale for Sweat Sensing

Many natural organizations with some special functional properties possess fractal tissues which display nearly the same at every scale. The benefit of mimicking fractal structure in synthetic functional materials warrants further exploration. To tackle this challenge, we assemble metal-organic frameworks (MOFs) into fractal structures by using a bottom-up approach inspired from evaporation-driven crystallization. Such hierarchically branched MOFs exhibit some unexpected performances in electrochemistry, and can be a versatile biosensor for sweat analysis. Our work provides an interesting and efficient example for fabricating fractal MOFs as well as uncovering their new properties. This fractal-guided strategy can be extended to synthesize and explore new characteristics of other materials, holding potential in various applications including sensors, catalysis, and energy storage.