Ferroelectric Perovskite Oxide@TiO2 Nanorod Heterostructures: Preparation, Characterization, and Application as a Platform for Photoelectrochemical Bioanalysis.

This work reports the first synthesis and characterization of a ferroelectric perovskite oxide-based heterostructure as well as its application for photoelectrochemical (PEC) bioanalytical purposes. Specifically, exemplified by [KNbO3]1- x[BaNi1/2Nb1/2O3-δ] x (KBNNO), the ferroelectric perovskite oxides were prepared by solid-state synthesis, while the TiO2 nanorod (NR) arrays were obtained via a hydrothermal method. Using the technique of pulsed laser deposition (PLD), KBNNO were then deposited on TiO2 NRs to form KBNNO@TiO2 NR heterostructures. Various characterization techniques were applied to reveal compositional and structural information on the as-fabricated sample, and favorable alignment existed between the two components as displayed by the PEC test. In the detection of l-cysteine, the as-fabricated KBNNO@TiO2 NRs demonstrated good performance in terms of sensitivity and selectivity. This work revealed the potential of ferroelectric perovskite oxide and its heterostructures for innovative PEC bioanalytical applications, and we hope it will generate more interest in the development of various ferroelectrics-based heterostructures for advanced PEC bioanalysis.