Development of a molecularly imprinted photoelectrochemical sensing platform based on NH2-MIL-125(Ti)–TiO2 composite for the sensitive and selective determination of oxtetracycline

• Published in: Biosensors & bioelectronics Vol. 177; p. 113000
• Main Authors: Yang, Yukun, Yan, Wenyan, Wang, Xiaomin, Yu, Ligang, Zhang, Jinhua, Bai, Baoqing, Guo, Caixia, Fan, Sanhong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2021
• Subjects: Metal-organic framework; Molecularly imprinted polymer; Oxytetracycline; Photoelectrochemical sensor; TiO2; Photoelectrochemical sensor; Oxytetracycline; Metal-organic framework; Molecularly imprinted polymer; TiO2
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2021.113000

In this work, a molecularly imprinted photoelectrochemical (MIP-PEC) sensor based on a novel PEC composite of metal-organic frameworks (MOFs) and TiO2 (NH2-MIL-125(Ti)–TiO2) was established for the ultrasensitive and selective detection of oxytetracycline (OTC). This is the first attempt of applying MOFs in the construction of MIP-PEC sensor. The NH2-MIL-125(Ti)–TiO2 was synthesized by a simple one-step solvothermal method and modified onto the surface of indium tin oxide (ITO) electrode as the photosensitive layer. Subsequently, molecularly imprinted polymer (MIP) was modified as recognition element by electropolymerization. The NH2-MIL-125(Ti)–TiO2 showed an enhanced photocurrent response due to stronger light absorption capacity and matched energy band. Furthermore, MIP greatly improved the selectivity and sensitivity of the constructed PEC sensor. The photocurrent response of the MIP-PEC sensor was reduced after OTC recognition because the specific binding of OTC to the imprinted cavities blocked the electron transfer of the electrode. Under optimal experimental conditions, the MIP-PEC sensor exhibited a wide detection range from 0.1 nM to 10 μM with a low limit of detection (LOD) of 60 pM, as well as certain reproducibility, stability and good applicability in real samples. The proposed sensor provides ideas for the application of MOFs in the construction of PEC sensors and will offer an alternative method for the detection of other pollutants in the field of food safety. •A novel MIP-PEC sensor was prepared for the detection of OTC.•NH2-MIL-125(Ti)–TiO2 composite was used as photoelectrical converter of the sensor.•This is a first attempt of applying MOFs in the field of MIP-PEC sensor.•The MIP-PEC sensor exhibited good sensitivity, selectivity and applicability.