Ag nanoparticles/PbTiO3 with in-situ photocatalytic process and its application in an ultra-sensitive molecularly imprinted hemoglobin detection

Abstract

An electrochemical sensor based on loading molecularly imprinted polymers (MIP) on the material surface can improve the specificity towards the object. In this work, a T-shaped PbTiO3 with a high active-exposed (110) facet was prepared by a hydrothermal process. Then, Ag nanoparticles (Ag NPs) modified T-shaped PbTiO3 was obtained by in-situ photocatalytic reduced method under UV irradiation, where a hetero-junction was formed with a well lattice matching between the (111) facet of Ag0 and the (110) facet of PbTiO3. A MIPs modified by Ag nanoparticles (NPs)/PbTiO3 (MAP) electrodes was prepared via electro polymerization process by o-Phenylenediamine (o-PD) in the presence of the template molecule, bovine hemoglobin (BHb), i.e., the detected molecule. The response peak current and concentration of BHb is demonstrated with a good linear relationship in the range of 0.00294–0.41 nM (R2 =0.98), and the detection limit at 0.23 pM (S/N = 3). A heterojunction between Ag NPs and high- active facet of PbTiO3 is beneficial to oxidizing electroactive material ([Fe (CN)6]3-/4-), generating more BHb-imprinting cavities on the modified electrode and improving the sensitivity of sensor. The electrochemical sensor is with a simple, stable structure and high sensitivity to BHb detection. Furthermore, the sensor was successfully applied to detect BHb in the bovine serum samples.