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 x 10(-9) to 2 x 10(-6)m 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.