Engineering a novel rhodamine-based fluorescent probe using host-guest interactions for reversible, selective, and sensitive detection of herbicide paraquat

• Published in: Sensors and actuators. B, Chemical Vol. 383; p. 133556
• Main Authors: Tang, A.-Ling, Yang, Lin-Lin, Tan, Shuai, Fan, Si-Li, Ma, Wen-Jing, Chen, Jie-Ying, Yang, Ping, Zhou, Xiang, Liu, Li-Wei, Wang, Pei-Yi, Yang, Song
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.05.2023
• Subjects: Cucurbituril; Host-guest interaction; Paraquat; Rhodamine; Rhodamine; Paraquat; Host-guest interaction; Cucurbituril
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2023.133556

Although paraquat (PQ) is one of the most extensively used herbicides worldwide, it is hazardous to the environment and the public due to its extreme toxicity towards non-target organisms especially animals and humans. Therefore, developing a detection system for selectively and sensitively detecting PQ remains a great challenge. This report demonstrates the design of a novel highly fluorescent rhodamine-based probe fabricated by rationally inserting adamantane-modified rhodamine into a host cucurbit[7]uril (CB[7]) with a host-guest interaction induced spirocyclic ring-opening process. This host-guest binary complex (1&CB[7]) had a stronger fluorescence intensity than rhodamine B, which was exploited for PQ detection. Notably, complex 1&CB[7] displayed high sensitivity toward PQ, with an excellent nanomolar limit of detection of 10 nM. It was determined that this unique detection mechanism involved a process of self-assembly, disassembly, and reassembly, thereby providing a reversible fluorescence response to PQ. With such merits, we successfully quantified and mapped PQ in actual water samples, live cells, and various agricultural products. We anticipated that the constructed complex 1&CB[7] could acts as a potential alternative for PQ tracking in various applications, highlighting a new paradigm for engineering host-guest probes with spirocyclic ring-opening process for analyte detection. [Display omitted] •A new fluorescent supramolecular probe is fabricated by adamantane-modified rhodamine B and cucurbit[7]uril.•The supramolecular complex can selectively, sensitively, and reversible detect herbicide paraquat through host-guest interaction.•A reversible detection system is realized with host-guest interaction induced spirocyclic ring-opening process.•The supramolecular probe is useful for visual detecting paraquat in actual samples including water and agricultural products.