Metal-organic framework-based materials as an emerging platform for advanced electrochemical sensing

Recent progress in the design fabrication of metal-organic frameworks-based nanozymes and their applications to sensing and cancer therapy.

Food safety as a huge world public health threat has attracted more and more attentions. The effective detection methods are of great importance for guarding food safety. However, the development of reliable and efficient detection methods has been a challenging task due to the complexity of food matrices and trace level of food contaminants. Recently, the emerging nanomaterials with mimetic enzyme activity, namely nanozymes, have been employed for novel biosensor development, which has greatly accelerated the advancement of food safety assay. In this review, we summarize the mechanism and advances on nanozymes-based biosensors including colorimetric biosensors, fluorescence biosensors, chemiluminescent biosensors, electrochemical biosensors, SERS-based biosensors, and other biosensors. Impressively, the applications of nanozymes-based biosensors in food safety screening have also been comprehensively summarized (including mycotoxins, antibiotics, pesticides, pathogens, intentional adulteration, metal ions, and others). In the end, future opportunities and challenges in this promising field are tentatively proposed.

Recent progress in the construction of nanozyme-based biosensors and their applications to food safety assay

Construction of MOF-based superhydrophobic composite coating with excellent abrasion resistance and durability for self-cleaning, corrosion resistance, anti-icing, and loading-increasing research

Nanomaterial-based enzyme-mimetic catalysts (Enz-Cats) have received considerable attention because of their optimized and enhanced catalytic performances and selectivities in diverse physiological environments compared with natural enzymes. Recently, owing to their molecular/atomic-level catalytic centers, high porosity, large surface area, high loading capacity, and homogeneous structure, metal-organic frameworks (MOFs) have emerged as one of the most promising materials in engineering Enz-Cats. Here, the recent advances in the design of MOF-engineered Enz-Cats, including their preparation methods, composite constructions, structural characterizations, and biomedical applications, are highlighted and commented upon. In particular, the performance, selectivities, essential mechanisms, and potential structure-property relations of these MOF-engineered Enz-Cats in accelerating catalytic reactions are discussed. Some potential biomedical applications of these MOF-engineered Enz-Cats are also breifly proposed. These applications include, for example, tumor therapies, bacterial disinfection, tissue regeneration, and biosensors. Finally, the future opportunities and challenges in emerging research frontiers are thoroughly discussed. Thereby, potential pathways and perspectives for designing future state-of-the-art Enz-Cats in biomedical sciences are offered.

Metal–Organic‐Framework‐Engineered Enzyme‐Mimetic Catalysts

Herein, an electrochemical sensing platform based on Cu-based metal-organic framework (Cu-MOF) decorated with gold nanoparticles (AuNPs) is constructed for the sensitive detection of nitrite. Cu-MOF was synthesized by a simple wet chemical synthesis at room temperature. AuNPs were electrodeposited on Cu-MOF modified glass carbon electrode (Cu-MOF/GCE) using potentiostatic method. The AuNPs decorated Cu-MOF (Cu-MOF/Au) displays synergetic catalytic effect for the oxidation of nitrite due to the large surface area and porosity of Cu-MOF, which could prevent the aggregation of AuNPs and increase the adsorption of nitrite, combining with the high conductivity and excellent catalytic activity of AuNPs. A nitrite sensing platform was constructed based on Cu-MOF/Au/GCE, and amperometric technique was adopted for quantitative determination of nitrite. The prepared electrochemical sensing platform demonstrates high sensitivity, selectivity and good stability for the detection of nitrite. It shows two wide linear ranges of 0.1–4000 and 4000–10000 μM, and the low detection limit of 82 nM. Moreover, the sensing platform can also be used for the nitrite detection in real samples. This work would broaden the application of MOFs material in constructing more novel electrochemical sensing platforms.

Faqian Liu

Papers

Electrodeposition of gold nanoparticles on Cu-based metal-organic framework for the electrochemical detection of nitrite