Novel material from natural resource, Agarose with clustering-triggered emission and its diverse applications

In recent years, non-conjugated materials with fluorescence emission characteristics have attracted much attention due to their promising application in different fields. However, most traditional materials require complex organic synthesis and even has toxicity. Here, we report a non-conjugated biomass material, agarose (Aga), which hardly has any fluorescent emission in dilute solution, but can emit strong fluorescence when its aggregates formed. In addition, we have observed room temperature phosphorescence (RTP) of Aga powders, which is also unusual in pure organic nonaromatic materials. The fluorescent emission of Aga could be illustrated by the clustering-triggered emission (CTE) mechanism, namely, the accumulation of untraditional chromophores with π and n electrons and the subsequent overlap of electron clouds play a crucial role in luminescence. At the same time, Aga can be employed as a fluorescent probe for multi-channel imaging. Moreover, Aga solution exhibits a sensitive quenching effect on Fe³⁺, thus, it can be used as a biosensor for detecting the concentration of Fe³⁺. These Results all shown that Aga can be used as a novel AIE material and will have broad application fields.