Dual-mode fluorescence/colorimetric detection of aniline via a perovskite quantum dots-functionalized Eu-MOFs platform

Aniline, a toxic volatile organic compound, presents considerable risks to human health and environmental safety. In this study, we have developed a novel composite fluorescent probe, named as CPB@Eu-MOFs, fabricated through the integration of perovskite quantum dots (CPB) into a europium-based metal-organic frameworks (Eu-MOFs). This composite serves as a self-calibrating, ratiometric fluorescent probe for the detection of aniline. It exhibits high selectivity towards aniline over common interfering volatile organic compounds, as well as a high sensitivity with a detection limit of 4.72 × 10 −6  M and a wide linear response range from 5 × 10 −4 to 10 −1  M. A distinct photoluminescence color evolution from red to orange, yellow, green and finally blue is observed with increasing aniline concentration, enabling rapid visual quantification alongside instrumental analysis. This work proposes a convenient and reliable dual-mode sensing strategy, combining visual and ratiometric fluorescence readouts, for monitoring aniline in environmental and industrial safety applications.