Cesium Lead Halide Perovskite Quantum Dots as a Photoluminescence Probe for Metal Ions

Perovskite structured CsPbX₃ (X = Cl, Br or I) quantum dots (QDs) have attracted great attention in the past few years for appealing application potentials in photovoltaic and optoelectronic devices. In this report, the CsPbX₃ QDs are shown to perform as a new probe for metal ions with high sensitivity, high selectivity and instant response by the quenching or enhancing of the photoluminescence (PL). Through experimental and calculation efforts, the probing mechanisms are investigated. A wide probing window for Cu²⁺ and Yb³⁺ ions ranging from 2 × 10⁻⁹ to 2 × 10⁻⁶m is exhibited for CsPbBr₃ QDs. In practice, the CsPbBr₃ QDs are successfully applied for fast probing Cu²⁺ ions in edible oils and vehicle lubricating oils with the precision consistent to the values measured by inductively coupled plasma (ICP). Thus, it provides a promising powerful tool in detecting certain metal ions in biological and industrial organic solution systems.