Fluorescence Sensing of Bilirubin Using Water-Stable Ethylenediaminetetraacetic Acid-Functionalized CsPbBr₃ Perovskite Quantum Dots

In recent years, lead-containing perovskite quantum dots (PQDs) have sparked a great deal of research in sensing applications as a result of their exceptional optoelectronic characteristics. However, due to their poor stability in ambient air and polar solvents such as water, they are not suitable as probes to detect analytes under aqueous conditions. The present study introduces a rapid and simple fluorescent approach for the sensing of bilirubin (BR) using ultrasonication-assisted synthesis of ethylenediaminetetraacetic acid functionalized CsPbBr3 PQDs (EDTA@CsPbBr3 PQDs) as optical nanoprobes. The as-prepared EDTA@CsPbBr3 PQDs displayed intense green fluorescence under UV light (365 nm) with excellent water stability. The fluorescence emission intensity (at 525 nm) of EDTA@CsPbBr3 PQDs was drastically decreased with the introduction of BR via an inner filter effect mechanism. The developed method for the assay of BR exhibited a broad linear range of concentration (0.05–25 μM) and low limit of detection (15.94 nM) with good selectivity. This study could open a path for the fabrication of water-dispersed PQDs with selective identification of BR, which is essential for sensing applications.