23 †Contributed equally to this work 24 Main Text: 1 Fractional-dimensional (fractal) geometrya property of shapes that are invariant or nearly 2 invariant to scale magnification or contraction across many length scalesis a common feature of 3 many natural objects 1,2 . Fractal forms are ubiquitous in geology, e.g., in the architecture of 4 mountain ranges, coastlines, snowflakes, and in physiology, e.g., neuronal and capillary networks, 5 and nasal membranes, where highly efficient molecular exchange occurs due to a fractal-induced 6 high surface area:volume ratio 3 . Fabrication of fractal-like nanomaterials affords high physical 7 connectivity within patterned objects 4 , ultrasensitive detection of target binding moieties by 8