Natural evolution relies on the improvement of biological entities by rounds of diversification and selection. In the laboratory, directed evolution has emerged as a powerful tool for the development of new and improved biomolecules, but it is limited by the enormous workload and cost of screening sufficiently large combinatorial libraries. Here we describe the production of gel-shell beads (GSBs) with the help of a microfluidic device. These hydrogel beads are surrounded with a polyelectrolyte shell that encloses an enzyme, its encoding DNA and the fluorescent reaction product. Active clones in these manmade compartments can be identified readily by fluorescence-activated sorting at rates >107 GSBs per hour. We use this system to perform the directed evolution of a phosphotriesterase (a bioremediation catalyst) caged in GSBs and isolate a 20-fold faster mutant in less than one hour. We thus establish a practically undemanding method for ultrahigh-throughput screening that results in functional hybrid composites endowed with evolvable protein components. Evolution of Catalysts Caged in Biomimetic Gel-Shell Beads AbstractNatural evolution relies on improvement of biological entities by rounds of

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Herein, we demonstrate the synthesis of rGO/BiVO hybrid nanostructures by facile hydrothermal method. Morphological studies reveal that rGO sheets are embedded in the special dendritic fern-like structures of BiVO. The rGO/BiVO hybrid architecture shows the way to a rational design of supercapacitor, since these structures enable easy access of electrolyte ions by reducing internal resistance. Considering the unique morphological features of rGO/BiVO hybrid nanostructures, their supercapacitive properties were investigated. The rGO/BiVO electrode exhibits a specific capacitance of 151 F/g at the current density of 0.15 mA/cm. Furthermore, we have constructed rGO/BiVO symmetric cell which exhibits outstanding volumetric energy density of 1.6 mW h/cm (33.7 W h/kg) and ensures rapid energy delivery with power density of 391 mW/cm (8.0 kW/kg). The superior properties of symmetric supercapacitor can be attributed to the special dendritic fern-like BiVO morphology and intriguing physicochemical properties of rGO.