Eu-COF-based fluorescence and portable detection of acetone in exhaled breath

Exhaled biomarker detection, as a non-invasive and portable analytical method, holds great potential in the field of point-of-care testing. Acetone exhibits higher concentrations in the exhaled breath of diabetic patients compared to healthy individuals. Therefore, the development of highly sensitive, easy-to-operate, and portable acetone detection technology is desirable for the rapid screening of diabetes. A covalent organic framework, Eu-COF, was synthesized, and its fluorescence can be specifically quenched by acetone based on the mechanism of energy competition. A flexible Eu-COF-based fluorescent film, prepared using polyvinyl alcohol (PVA) as the substrate, was found to be suitable for use in a portable 3D printing device for on-site rapid detection of acetone. The linearity of concentration ranged from 0.2-8.0 mg m^-3, with a detection limit of 0.1 mg m^-3 (RSD = 8.6%). The accuracy of the device was validated by comparison with the results of GC-MS. Based on the <i>F</i>-test, there were no significant differences between the results of the portable device and GC-MS. The Eu-COF-based fluorescent film also exhibited a comparable response in humid environments. The detection device integrates sample collection and testing in one step, directly providing the concentration of acetone exhaled by the patient. It can serve as a rapid screening tool for point-of care, non-invasive diabetes detection.