Kaempferol as an AIE-active natural product probe for selective Al³⁺ detection in Arabidopsis thaliana

In this work, a natural product probe, kaempferol, which exhibited aggregation-induced emission (AIE) characteristic in water/tetrahydrofuran (THF) binary solvent was explored. The probe showed high resistance to photobleaching capacity and excellent selectivity towards Al³⁺ in the aggregation state. Upon the addition of Al³⁺, the probe displayed more than 12-fold (I₄₈₆/I₄₂₁) fluorescence intensity enhancement, accompanied by a color change, suggesting that the aggregated kaempferol can be used as a ratiometric probe for Al³⁺ detecting. Notably, promising selectivity to Al³⁺ within the pH range of 6-8 made the probe suitable for physiological conditions. Further Arabidopsis thaliana root imaging experiment demonstrated that the probe could image Al³⁺ in the plant.