Enzyme-inorganic hybrid nanoflowers: Classification, synthesis, functionalization and potential applications

Due to poor operational stability and hard recovery of enzymes in industrial applications, enzyme immobilization techniques have gained considerable development. However, there are still big obstacles to apply immobilized enzymes for practical applications. Recently, a novel hybrid nanomaterial, i.e., enzyme-inorganic hybrid nanoflowers (HNFs), has presented a series of superior performances. Herein, the classification, synthesis, functionalization and potential applications of enzyme-inorganic HNFs are reviewed. First, an optimized classification of enzyme-inorganic HNFs is proposed. Enzyme-inorganic HNFs are first categorized into single-enzyme and multi-enzyme HNFs, which are subdivided based on metal phosphates and application fields, respectively. Second, synthesis conditions are discussed to optimize the fabrication of enzyme-inorganic HNFs. Third, the highlight part of this review is that supported, magnetic, chemically modified and antibody-modified enzyme-inorganic HNFs are summarized to better recycle enzyme-inorganic HNFs and satisfy the requirements of specific applications. Fourth, the latest applications of enzyme-inorganic HNFs are concluded including biosensors, biocatalysis, dye decolorization, protein digestion, enzyme purification, biofuel cell, beer brewing and detergent industry. Last but not least, current problems and prospects are proposed to suggest further study of enzyme-inorganic HNFs.