title: Bovine Serum Albumin Adsorption in Mesoporous Titanium Dioxide: Pore Size and Pore Chemistry Effect.
abstract: Understanding the mechanism of protein adsorption and designing materials with high sensitivity, high specificity and fast response are critical to develop the next-generation biosensing and diagnostic platforms. Mesoporous materials with high surface area, tunable pores, and good thermal/hydrostatic stabilities are promising candidates in this field. Because of the excellent biocompatibility, titanium dioxide has received an increasing interest in the past decade for biomedical applications. In this work, we synthesized mesoporous titanium dioxide with controlled pore sizes (7.2-28.0 nm) and explored their application for bovine serum albumin (BSA) adsorption. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption/desorption experiments were performed to characterize the mesoporous TiO2 samples before and after BSA adsorption. Isothermal microcalorimetry was applied to measure both the adsorption heat and conformation rearrangement heat of BSA in those mesopores. We also carried out thermogravimetry measurements to qualitatively estimate the concentration of hydroxyl groups, which plays an important role in stabilizing BSA in-pore adsorption. The adsorption stability was also examined by leaching experiments. The results showed that TiO2 mesopores can host BSA adsorption when their diameters are larger than the hydrodynamic size of BSA (∼9.5 nm). In larger mesopores studied, two BSA molecules were adsorbed in the same pores. In contrast to the general understanding that large mesopores demonstrate poor stabilities for protein adsorptions, the synthesized mesoporous TiO2 samples demonstrated good leaching stabilities for BSA adsorption. This is probably due to the combination of the mesoporous confinement and the in-pore hydroxyl groups.
authors.affiliation: College of Chemical Engineering, Nanjing Tech University , Nanjing 210009, China.|School of Chemical, Biological & Materials Engineering, University of Oklahoma , Norman, Oklahoma 73019, United States.|Jiangnan Graphene Research Institute, Changzhou 213149, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: College of Chemical Engineering, Nanjing Tech University , Nanjing 210009, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Guo
authors.affiliation: College of Chemical Engineering, Nanjing Tech University , Nanjing 210009, China.
authors.forename: Qiliang
authors.initials: Q
authors.lastname: Hong
authors.affiliation: College of Chemical Engineering, Nanjing Tech University , Nanjing 210009, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Rao
authors.affiliation: College of Chemical Engineering, Nanjing Tech University , Nanjing 210009, China.
authors.forename: Haijuan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: College of Chemical Engineering, Nanjing Tech University , Nanjing 210009, China.
authors.forename: Yihui
authors.initials: Y
authors.lastname: Dong
authors.affiliation: School of Chemical, Biological & Materials Engineering, University of Oklahoma , Norman, Oklahoma 73019, United States.
authors.forename: Liangliang
authors.initials: L
authors.lastname: Huang
authors.affiliation: College of Chemical Engineering, Nanjing Tech University , Nanjing 210009, China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Lu
authors.affiliation: Jiangnan Graphene Research Institute, Changzhou 213149, China.
authors.forename: Ningzhong
authors.initials: N
authors.lastname: Bao