A novel dual-emission QDs/PCDs assembled composite nanoparticle for high sensitive visual detection of Hg2+

Traditional fluorescent probe detection is an established technique for enhancing or quenching luminescence intensity; however, a color changeable fluorescent material is still a challenge in many target detection fields. Herein, a dual-emission quantum dots (QDs)/polymer carbon dots (PCDs) assembled composite nanoparticle was prepared via a simple self-assembly method. By choosing the QDs and PCDs source, the luminescence color of the composite nanoparticles can be controlled all over the visible light spectrum. The composite material possesses high sensitivity and selectivity with Hg2+; with increasing concentration of Hg2+, the luminescence color of the composite material changes from pink to violet, and at last blue. The detection limit of Hg2+ was 10 nM by luminescence spectrum, and 100 nM by visual observation, so it may be utilized for visual detection in environmental science and biology.