Promoting the transfer of phosphorescence from the solid state to aqueous phase and establishing the universal real-time detection based on the smartphone imaging

Currently, room-temperature phosphorescent (RTP) materials inspire the great interest owing to their tunable wavelengths, large stokes shift or potential values towards various applications. Howbeit, synthesizing RTP materials with the desirable property such as the long lifetime still encountered the intractable challenge due to the spin-forbidden nature of triplet exciton transitions. Here we initially achieved one kind of solid state phosphorescence by preparing the carbon dots (CDs) doped with nitrogen and phosphorus while diethanolamine and phosphoric acid served as the specific precursors. Significantly, the CDs were effectively protected away from the interference of water and oxygen in the surrounding environment through introducing tetraethyl orthosilicate, thus leading to the successful emergence of their phosphorescence in aqueous. This study not only provided a way of activating the phosphorescent emission from the solid state to aqueous phase, but also broadened the sensing avenues based on the aqueous phosphorescence. Since both their fluorescence and phosphorescence intensity of the CDs were regularly quenched based on the inner filter effect (IFE) by adding p-nitrophenol with various concentrations, we thereupon proposed a regular dual-channel strategy for detecting p-nitrophenol. More meaningfully, both the Hue and Brightness of their fluorescence and phosphorescence of CDs exhibited obvious distinctions, providing the possibility of establishing a dual-channel smartphone assaying strategy through directly photographing. Thus, we hereby raised a convenient intelligent detection of p-nitrophenol, and this brand-new way not only achieved the real-time detection of p-nitrophenol, but also showed the possibility of serving as a universal approach for detecting other targets on-site. • A routine dual-channel assay of p-nitrophenol was originally established. • Activating the phosphorescence from solid state to aqueous phase was achieved. • The universal real-time detections were proposed based on smartphone imaging.