A portable self-calibrating logic detector for gradient detection of formaldehyde based on luminescent metal organic frameworks

Abstract

Trace quantities of formaldehyde (FA) in water and food will cause great harm to the human body, and has received much attention in recent years. In this work, a luminescent metal organic framework (Eu³⁺@Bio-MOF-1) was successfully constructed to detect FA in water and food. Experiments show that the two luminescent centers of Eu³⁺@Bio-MOF-1 have completely different responses to FA and the two luminescent centers can offer a reference for each other, so it can be designed as a precise self-calibrating luminescent detector for FA. Based on this, a portable self-calibrating luminescent logic detector capable of gradient detection of FA is designed. The three different outputs of this logic detector are L (low), H (high), and VH (very high), corresponding to three different inputs (<6 ppm, 6–10 ppm, and >10 ppm). More importantly, the color differences can be easily distinguished by the naked eye under UV light, which makes a significant contribution to detect the concentration of FA more intuitively in our daily life.