Food Chemistry 395 (2022) 133642 Available online 7 July 2022 0308-8146/© 2022 Elsevier Ltd. All rights reserved. Engineering MOFs derived metal oxide nanohybrids: Towards electrochemical sensing of catechol in tea samples Tayyaba Iftikhar a , Ayesha Aziz b , Ghazala Ashraf b , Yun Xu a , Guangfang Li a , Tiansui Zhang a , Muhammad Asif a, * , Fei Xiao a, * , Hongfang Liu a, * a Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China b College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan 430074, PR China A R T I C L E INFO Keywords: Electrochemical sensor Cu-MOF/CuO/NiO nanocomposite Pollutant Catechol Black and green tea ABSTRACT In this work, we have successfully developed Cu-MOF/CuO/NiO nanocomposites (NCs) and employed as a novel electrochemical sensing platform in catechol (CC) detection. The Scanning electron microscopy (SEM) along Energy dispersive X-ray Analysis (EDX), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) are carried out to characterize the as-fabricated Cu-MOF/CuO/NiO NCs. Cyclic voltammetry (CV) and differential pulse voltam- metry (DPV) techniques have used to obtain oxidation peak currents of CC. Glassy carbon electrode (GCE) modifed with Cu-MOF/CuO/NiO has exposed the superb EC properties representing low limit of detection (LOD) of 0.0078 µM (S/N = 3). To assess the practicability of Cu-MOF/CuO/NiO based sensing medium, it has been used to detect CC from two varieties of tea, namely black and green. Thus, we anticipate that this structural integration strategy possesses encouraging application potential in sensing podium and material synthesis. 1. Introduction In modern era, catechol (1,2-dihydroxybenzene/1,2-benzenediol) plays a vital role in various natural sources including tea, fruits, tobacco, vegetables, and other plants as a signifcant dihydroxybenzene. Catechol (CC) is also contemplated as a key fragment of tea catechins (Zainudin et al., 2021). The most fatal dosage of CC for human beings is from 50 to 500 mg/kg or one ounce or one teaspoon given once to a 70 kg person. Additionally, high level of toxicity with low degradability of CC in ecological environment has classifed it into group II B which is human carcinogen and a periodic environmental contaminant. Therefore, simplest, reliable, and sensitive methods are needed to be developed instantly for CC detection. There are several analytical methods that are used for CC moni- toring, for instance high performance liquid chromatography (HPLC), gas chromatography (GC), spectrophotometry, and surface plasmon resonance etc. (Tahernejad-Javazmi et al., 2018; Tahernejad-Javazmi & Shabani-Nooshabadi, 2017). Nonetheless, these strategies have some drawbacks including poor selectivity, complicated operation, expensive and sample pre-treatment. While on the other hand, electrochemical sensing technology is fascinating the researchers as it is generally adopted in the analysis of environmental and biological samples due to its admirable features e.g. good selectivity as well as sensitivity, quick analytical reaction, simple equipment, cost-effective, and no sample pretreatment is required (Asif et al., 2021; Shabani-Nooshabadi & Tahernejad-Javazmi, 2015). However, the sensing performance depends on the composition of the electrode material (Darabi & Shabani- Nooshabadi, 2021; Iftikhar, et al., 2021). Currently, scientists are focusing their efforts on developing robust analytical procedures for monitoring phenolic compounds such as CC in industrial together with environmental specimens using metalorganic frameworks (MOFs) based sensors (Misaghpour & Shabani-Nooshabadi, 2018). They have also been utilized as ideal precursors for the ther- molysis synthesis of various useful materials like metal and their oxides with hybrid materials. Mostly, MOFs are expected to be insulators because of their less charge transport pathways. Several research have recently revealed the potential of MOFs for electrochemical sensing. For instance, Yuan et al. have developed novel 2D Co based MOF which * Corresponding authors. E-mail addresses: asif83chemist@gmail.com (M. Asif), xiaofei@hust.edu.cn (F. Xiao), liuhf@hust.edu.cn (H. Liu). Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem https://doi.org/10.1016/j.foodchem.2022.133642 Received 18 February 2022; Received in revised form 18 June 2022; Accepted 4 July 2022