This study describes the preparation of nanoprotein particles carrying horseradish peroxidase (HRP) and alkaline phosphatase (ALP) using a photosensitive microemulsion polymerization technique. The prepared nanoparticles having dual character were characterized by transmission electron microscopy (TEM) and Zeta Sizer. The average particle size of p(HRP-co-ALP) nanoparticles was found to be about 90 nm. The activity of nanoparticles having dual character was assayed using tetramethylbenzidine and paranitrophenyl phosphate (p-NPP) as substrates for HRP and ALP, respectively. The parameters such as pH, temperature and initial enzyme concentration that affect the activity were investigated by using p(HRP-co-ALP) nanoparticles and compared with the free HRP and ALP. The reusability of p(HRP-co-ALP) particles was also investigated and the results showed that the prepared nanoparticles exhibited admirable potential as a reusable catalyst. (C) 2015 Elsevier B.V. All rights reserved.