Cell Sheet-like Soft Nanoreactor Arrays.

Tissues, which consist of groups of closely packed cell arrays, are essentially sheet-like biosynthesis plants. In tissues, individual cells are discrete microreactors working under highly viscous and confined environments. This paper reports on soft polystyrene-encased nanoframe (PEN) reactor arrays as analogous nanoscale "sheet-like chemosynthesis plants" for the controlled synthesis of novel nanocrystals. Although the soft polystyrene (PS) was only 3 nm thick, it was elastic, robust, and permeable to aqueous solutes, while significantly slowing down their diffusion. PEN-associated palladium (Pd) crystallization followed a diffusion-controlled zero-order kinetics rather than a reaction-controlled first-order kinetics in bulk solution. Each individual PEN reactor had a volume in the zeptoliter range, which offered a unique confined environment, enabling a directional inward crystallization, in contrast to the conventional outward nucleation/growth that occurs in an unconfined bulk solution. This strategy made it possible to generate a set of mono-, bi-, trimetallic, and even semiconductor nanocrystals with tunable interior structures, which are difficult to achieve with normal systems based on bulk solutions. This article is protected by copyright. All rights reserved.