A novel core-shell nanomaterial ratiometric fluorescent probe for detecting urinary TDGA as a biomarker for VCM exposure

Thiodiglycolic acid (TDGA) is regarded as a sensitive biomarker for biological monitoring of VCM exposure. A simple, fast and reliable TDGA analysis method is of great significance to human health and the ecological environment. In this work, a novel core-shell nanomaterial based on p-type semiconductor@MOFs (Eu-CBO@Uio-66) is first prepared by in-situ growth and post-synthesis modification (PSM) as a ratiometric fluorescent probe for detecting TDGA, which shows a high sensitivity with a detection limit down to 51.1 μg L −1 (about 0.34 μM), relatively broad linear range (0–700 mg/L), fast response to TDGA within 2 min. As a result, after dispersing the resulting composite material in a solution containing TDGA, the blue emission of Eu-CBO@Uio-66 at 466 nm remains unchanged, while the red emission of Eu 3+ center at 615 nm is significantly quenched, even in coexistence with other potentially analytes in the urine, so that the peak height ratio of the two emissions could be employed for determining TDGA. In addition, the significant ratiometric luminescence response caused by TDGA makes Eu-CBO@Uio-66 undergo a significant color transition from red to blue under UV-lamp, which is beneficial for visual analysis with the naked eye.