Triacetone triperoxide (TATP) is synthesized from acetone and hydrogen peroxide under acid catalysis. Traditional TATP detection primarily relies on a two-step indirect method, which first requires using a strong acid to decompose TATP into hydrogen peroxide and acetone, followed by the detection of these products. However, this approach is hindered by operational complexity, lengthy processing times, and a high false positive rate due to interference from environmental hydrogen peroxide and acetone. Therefore, developing a one-step, highly sensitive, and specific direct detection method for TATP is crucial for safeguarding public security.

To address this challenge, a research team led by Prof. DOU Xincun from the Xinjiang Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences (CAS) has proposeda one-step fluorescence turn-on sensing strategy for TATP detection based on an H₂O-driven cascade reaction. Their findings, published in Aggregate, emphasize tuning the number of hydroxyl groups in ligands to decrease background fluorescence and improve both the detection efficiency and the signal-to-noise ratio.

In this study, based on the intersystem crossing (ISC) mechanism, researchers designed and synthesized three nonfluorescent Eu-MOFs.It was found that when the ligand was 2,5-dihydroxyterephthalic acid (DHTA), the introduction of a small amount of H₂O could trigger the cascade reaction of Eu-MOF-3 toward TATP. That is, H₂O molecules first convert the strong intramolecular hydrogen bond of the ligand in Eu-MOF-3 into a weaker intermolecular hydrogen bond. The strong oxidizing property of TATP further breaks this hydrogen bond and oxidizes the ligand from the enol structure to the ketone structure. The nonfluorescent Eu-MOFs design strategy based on cascade reaction proposed in this work achieves one-step, rapid (<1 s), ultra-sensitive (LOD = 36.1 nM), and highly specific detection of TATP. This approach effectively resolves the complex operational procedures and susceptibility to interference from environmental hydrogen peroxide and acetone associated with traditional two-step detection methods. Furthermore, the development of a glass fiber-based sensing film and a portable detection system verified the outstanding performance of this strategy for detecting trace TATP particles in practical, on-site applications, which provides a research methodology for the functional customization of MOFs materials and the development of novel sensing systems.

This study was published in Aggregate with the title of “One-Step, Specific and Fluorescent Sensing of pg-Level TATP via Intramolecular Hydrogen Bond Breaking in Eu-MOFs” .

Figure:Schematic illustration of the Eu-MOF design strategy and the mechanism for TATP detection. (Image by XTIPC)