Although the immobilization of enzymes with improved activity and stability has been the subject of growing interest for many years, new opportunities arose by implementing nanomaterials as immobilizing carriers. The nano-carriers not only offer larger surface area and lower mass-transfer limitation but also endow the native enzyme with specific performances due to their various physical or chemical properties. A carrier-free nanobiocatalyst, cross-linked enzyme aggregates (CLEAs), has been developed for applications in industrial bioprocesses. This review illustrates the recent achievements in nanobiocatalysts, including the carrier-bound and carrier-free enzymes. These nanobiocatalysts provide enzymes with broad properties to serve in the fields of biocatalysis, biomedicine and biosensors. (C) 2015 Elsevier Ltd. All rights reserved.