Fluorescence Sensing\nof Bilirubin Using Water-Stable\nEthylenediaminetetraacetic Acid-Functionalized CsPbBr<sub>3</sub> Perovskite\nQuantum Dots

In recent years, lead-containing perovskite quantum dots\n(PQDs)\nhave sparked a great deal of research in sensing applications as a\nresult of their exceptional optoelectronic characteristics. However,\ndue to their poor stability in ambient air and polar solvents such\nas water, they are not suitable as probes to detect analytes under\naqueous conditions. The present study introduces a rapid and simple\nfluorescent approach for the sensing of bilirubin (BR) using ultrasonication-assisted\nsynthesis of ethylenediaminetetraacetic acid functionalized CsPbBr<sub>3</sub> PQDs (EDTA@CsPbBr<sub>3</sub> PQDs) as optical nanoprobes.\nThe as-prepared EDTA@CsPbBr<sub>3</sub> PQDs displayed intense green\nfluorescence under UV light (365 nm) with excellent water stability.\nThe fluorescence emission intensity (at 525 nm) of EDTA@CsPbBr<sub>3</sub> PQDs was drastically decreased with the introduction of BR\nvia an inner filter effect mechanism. The developed method for the\nassay of BR exhibited a broad linear range of concentration (0.05–25\nμM) and low limit of detection (15.94 nM) with good selectivity.\nThis study could open a path for the fabrication of water-dispersed\nPQDs with selective identification of BR, which is essential for sensing\napplications.