Aham Emmanuel Chigozie, Ravikumar A, Arunjegan A, Tamilselvan G, Hu Zhang, Xiao Jiaxuan, Zhang Zhen, Zhao Hongjun
School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China.
Department of Biochemistry, Faculty of Biological Sciences, University of Nigeria, Nsukka, Nigeria.
Mikrochim Acta. 2025 Jan 3;192(1):51. doi: 10.1007/s00604-024-06873-5.
A smartphone-integrated colorimetric sensor is introduced for the rapid detection of phenolic compounds, including 8-hydroquinone (HQ), p-nitrophenol (NP), and catechol (CC). This sensor relies on the peroxidase-mimicking activity of aspartate-based metal-organic frameworks (MOFs) such as Cu-Asp, Ce-Asp, and Cu/Ce-Asp. These MOFs facilitate the oxidation of a colorless substrate, 3,3',5,5'-tetramethylbenzidine (TMB), by reactive oxygen species (ROS) derived from hydrogen peroxide (HO), resulting in the formation of blue-colored oxidized TMB (ox-TMB). Among the synthesized MOFs, Cu/Ce-Asp nanorods had the highest activity, probably due to the synergistic effect of aspartate and copper coordination, as well as their large surface area, which allows for improved electron transport. Consequently, Cu/Ce-Asp nanorods were utilized for the detection of phenolic compounds under optimized conditions. In the presence of phenolic compounds, the interaction between TMB and HO is inhibited, resulting in various colorimetric responses. This method accurately determined HQ, NP, and CC in a linear range of up to 5 μM, with detection limits of 0.30 μM, 0.76 μM, and 0.50 μM, respectively. To facilitate real-time and portable analysis, smartphone technology was integrated for color detection, eliminating the need for expensive and bulky laboratory-based optical instruments. In addition, the sensor was effectively employed for real water sample analysis, yielding satisfactory recovery outcomes. The proposed sensor offers a rapid, user-friendly, and portable method for detecting phenolic compounds, even at low concentrations. This study not only advances the application of MOF-based nanozymes in environmental monitoring but also expands their potential use in other fields.
本文介绍了一种集成在智能手机上的比色传感器，用于快速检测酚类化合物，包括对苯二酚（HQ）、对硝基苯酚（NP）和邻苯二酚（CC）。该传感器依赖于基于天冬氨酸的金属有机框架（MOF）如Cu-Asp、Ce-Asp和Cu/Ce-Asp的过氧化物酶模拟活性。这些MOF促进无色底物3,3',5,5'-四甲基联苯胺（TMB）被过氧化氢（HO）产生的活性氧（ROS）氧化，导致形成蓝色氧化TMB（ox-TMB）。在合成的MOF中，Cu/Ce-Asp纳米棒具有最高的活性，这可能归因于天冬氨酸和铜配位的协同效应以及它们较大的表面积，这有利于改善电子传输。因此，在优化条件下，Cu/Ce-Asp纳米棒被用于检测酚类化合物。在酚类化合物存在的情况下，TMB和HO之间的相互作用受到抑制，从而产生各种比色响应。该方法在高达5 μM的线性范围内准确测定了HQ、NP和CC，检测限分别为0.30 μM、0.76 μM和0.50 μM。为了便于实时和便携式分析，集成了智能手机技术进行颜色检测，无需昂贵且笨重的基于实验室的光学仪器。此外，该传感器有效地用于实际水样分析，获得了令人满意的回收率结果。所提出的传感器提供了一种快速、用户友好且便携式的方法来检测酚类化合物，即使在低浓度下也是如此。这项研究不仅推进了基于MOF的纳米酶在环境监测中的应用，还扩展了它们在其他领域的潜在用途。
