A novel resonance Rayleigh scattering assay for trace formaldehyde detection based on Ce-MOF probe and acetylacetone reaction

Abstract

Formaldehyde (HCHO) is a widespread toxic pollutant, and the content of formaldehyde in food directly affects human health. Therefore, it is particularly important to establish and develop a rapid and accurate method for the determination of trace formaldehyde to ensure food safety. Metal-organic framework (MOF) has the characteristics of both organic and inorganic materials, which can be applied in various fields. What's more, Cerium (Ce) is the most abundant rare earth element. So far, it has no report about using Ce-MOF as a molecular probe of resonance Rayleigh scattering (RRS). The purpose of this research is to establish a new method for formaldehyde by combining the highly selective acetylacetone reaction with the sensitive RRS technology. When formaldehyde is added, acetylacetone reacts with it to form a complex (DDL), which acts as an accepter. There is a RRS-energy transfer (ET) between the DDL and Ce-MOF (act as the donor) because of spectral overlap. As a result, the RRS intensity of the Ce-MOF system decreased with formaldehyde concentration increase. So, Ce-MOF is used as a molecular probe of RRS to detect formaldehyde. In this study, the detection limit of formaldehyde was 0.063 µmol/L, and the determination range was 0.067–66.67 µmol/L. Compared with other methods, this method is simple in pretreatment and operation, and has a lower detection limit. Thus, a convenient detection of trace formaldehyde is realized.