Novel Tripodal-pillar[5]arene-based Chemical Sensor for Efficient Detection and Removal Paraquat by Synergistic Effect

Abstract Paraquat (PQ) plays a vital role in pesticide field, however, PQ always threatenhuman health owing to its high toxicity. Efficient detection and removal of PQ is an important and challenging task. Herein, a novel tripodal tri-pillar[ 5 ]arene-based sensor molecule (TP5) has been designed and synthesized. Interestingly, the designed tripodal tri-pillar[ 5 ]arene structure could offer a “synergistic effect” for the binding of PQ and achieve the fluorescence sensing. Through the “synergistic effect”, two adjacent pillar[ 5 ]arene groups in each TP5 molecule could bind one PQ molecule by multi-non-covalent interactions. Based on the “synergistic effect”, the sensor molecule TP5 has better sensing and removal efficiency toward PQ. The TP5 shows sensitivity fluorescence response for PQ and its lowest of detection limit (LOD) was 2.23 × 10-7 M. Meanwhile, TP5-based test paper has been prepared, which could serve as a convenient and efficient test kit to detect PQ in water and the concentration range is 10-6 M ∼ 10-1 M in practical situations. Furthermore, the TP5 displayed the excellent ability for PQ adsorption in water. For example, the TP5 was applied to absorb commercial pesticide paraquat (PQ), the adsorption efficiency for PQ was up to 98.40%. It is worth mentioning that, benefited from the “synergistic effect”, the TP5 shows better adsorption property than activated charcoal and most single pillar[n]arene based adsorption materials.