Perovskite-type calcium titanate nanoparticles as novel matrix for designing sensitive electrochemical biosensing.

In this work, novel perovskite-type calcium titanate nanoparticles (CaTiO 3 NPs) were for the first time exploited for the immobilization of proteins and the development of electrochemical biosensor. The CaTiO 3 NPs were synthesized with a simple and cost-effective route at low temperature, and characterized by scanning electron microscopy, X-ray photoelectron spectroscopic spectrum, electrochemical impedance spectrum, UV–visible spectroscopy, Fourier transform infrared spectrum, and cyclic voltammetry, respectively. The results indicated that CaTiO 3 NPs exhibited large surface area, and greatly promoted the direct electron transfer between enzyme molecules and electrode surface. The immobilized enzymes on this matrix retained its native bioactivity and exhibited a surface controlled, quasi-reversible two-proton and two-electron transfer reaction with an electron transfer rate of 3.35 s −1 . Using glucose oxidase as model, the prepared glucose biosensor showed a high sensitivity of 14.10±0.5 mA M −1 cm −2 , a wide linear range of 7.0×10 −6 to 1.49×10 −3 M, and a low detection limit of 2.3×10 −6 M at signal-to-noise of 3. Moreover, the biosensor also possessed good reproducibility, excellent selectivity and acceptable storage life. This research provided a new-type and promising perovskite nanomaterials for the development of efficient biosensors. [ABSTRACT FROM AUTHOR]