Metal-organic framework-based sensors for nitrite detection: a short review

Nitrite contamination in food and the environment has attracted incredible public attention owing to its detrimental effects on living systems. It is crucial to develop rapid, easy-to-use, accurate, and cheap analytical techniques to monitor nitrite levels. Metal-organic frameworks are a type of inorganic-organic hybrid crystal material known for their ultrahigh surface area, ordered porous structure, ease of function, as well as their catalytic activity or luminescence in certain situations. This allowed researchers to design a diverse array of sensors for the measurement of nitrite. This article highlights recent progress on the application of metal-organic frameworks towards the sensing of nitrite based on their unique electrical and optical features. According to the design strategies, electrochemical sensors based on metal-organic frameworks can be classified as pristine metal-organic frameworks, metal-organic framework composites, or metal-organic framework derivatives, while optical sensors can be divided into two classes, luminescent metal-organic frameworks, and metal-organic frameworks with luminescent guests. Each category was herein discussed and examples were provided. At the end of the review, current challenges and future trends are also addressed.