Nanomaterials as signal amplification elements in aptamer-based electrochemiluminescent biosensors

Nanoparticles containing magnetic materials, such as magnetite (Fe3O4), are particularly useful for imaging and separation techniques. As these nanoparticles are generally considered to be biologically and chemically inert, they are typically coated with metal catalysts, antibodies or enzymes to increase their functionality as separation agents. Here, we report that magnetite nanoparticles in fact possess an intrinsic enzyme mimetic activity similar to that found in natural peroxidases, which are widely used to oxidize organic substrates in the treatment of wastewater or as detection tools. Based on this finding, we have developed a novel immunoassay in which antibody-modified magnetite nanoparticles provide three functions: capture, separation and detection. The stability, ease of production and versatility of these nanoparticles makes them a powerful tool for a wide range of potential applications in medicine, biotechnology and environmental chemistry.

An updated comprehensive review to help researchers understand nanozymes better and in turn to advance the field. Nanozymes are nanomaterials with enzyme-like characteristics ( Chem. Soc. Rev. , 2013, 42 , 6060–6093). They have been developed to address the limitations of natural enzymes and conventional artificial enzymes. Along with the significant advances in nanotechnology, biotechnology, catalysis science, and computational design, great progress has been achieved in the field of nanozymes since the publication of the above-mentioned comprehensive review in 2013. To highlight these achievements, this review first discusses the types of nanozymes and their representative nanomaterials, together with the corresponding catalytic mechanisms whenever available. Then, it summarizes various strategies for modulating the activity and selectivity of nanozymes. After that, the broad applications from biomedical analysis and imaging to theranostics and environmental protection are covered. Finally, the current challenges faced by nanozymes are outlined and the future directions for advancing nanozyme research are suggested. The current review can help researchers know well the current status of nanozymes and may catalyze breakthroughs in this field.