Surface functionalization of zirconium dioxide (ZrO2) nano-adsorbents was carried out by using 3-aminopropyl triethoxysilane (APTES) as the modifier. The addition amount of APTES was varied to determine the optimum modification extent, and the bulk ZrO2 microparticles were also modified by APTES for comparison. Some means, such as TEM, XRD, FT-IR, XPS and TG-DSC were used to character these ZrO2 particles. The results showed that the ANIS molecules were chemically immobilized on the surface of ZrO2 nanoparticles via Zr-O-Si bonds, and the nano-ZrO2 samples showed larger special surface area. In the adsorption of bovine serum albumin (BSA), nano-ZrO2 samples exhibited enhanced adsorption activity, and APTES Modified nano-ZrO2 with proper APTES content presented the best adsorption property. Under the same adsorption conditions, the equilibrium adsorption capacity of BSA on APTES-ZrO2-2 was almost 2.3 times as that on pristine nano-ZrO2 and 3.0 times as on bulk ZrO2 microparticles. The increased adsorption capacity of APTES-ZrO2 nano-adsorbents can be attributed to the chemical interaction between amino and carboxyl groups at APTES-ZrO2/BSA interface. The pH dependent experiments showed that the optimum pH value for the adsorption and desorption was 5.0 and 9.0, respectively, which suggested that the adsorption and release of BSA could be controlled simply by adjusting the solution pH condition. (C) 2016 Elsevier B.V. All rights reserved.