White emission magnetic nanoparticles as chemosensors for sensitive colorimetric and ratiometric detection, and degradation of ClO− and SCN− in aqueous solutions based on a logic gate approach

Abstract

Fluorescent chemosensors for detecting single anions have been largely synthesized. However, the simultaneous detection and degradation of multiple anions remain a major challenge. Herein we report the synthesis of a white emission nanoprobe on the basis of a Coumarin-Rhodamine CR1-Eu complex coordinated to dipicolinic acid (dpa)-PEG-Fe₃O₄ nanoparticles for the selective detection of ClO⁻ and SCN⁻ ions on controlling by a logic gate. The obtained nanoprobe exhibits three individual primary colors (blue, green, and red) as well as white emission at different excitation energies. Interestingly, this nanoprobe shows a marked rose red to violet emission color change in response to ClO⁻, a reversible violet to rose red emission color change in response to SCN⁻, and high ClO⁻ and SCN⁻ selectivity and sensitivity with a detection limit of 0.037 and 0.250 nM, respectively. Furthermore, the SCN⁻ and ClO⁻ can degrade simultaneously through the redox reaction between ClO⁻ and SCN⁻.