Preparation of a Fluorescent Polymer Sensing System with an Oxidation-Electric Dual-Mode Response Based on the Supramolecular Host–Guest Interaction

Nowadays, stimuli-responsive macromolecular self-assembly systems have significant potential in biomedicine and molecular regulation. Their combination with fluorescent molecules is particularly important in the design of a sensing system. In this work, we designed a stimuli-responsive fluorescent sensing system (PF-b-PFMMA-b-PPEGMA@CD) based on the self-assembly of cyclodextrins (CD) with ferrocene (Fc), which consisted of a water-soluble conjugated polymer composed of a polyfluorene backbone with fluorescent properties, a segment providing the self-assembled guest groups, and a segment improving water solubility, together with the modified cyclodextrin. The sensing system exhibited good sensitivity to oxidizing substances and electrical stimulation. Under self-assembly, the fluorescence of the aggregates was quenched. Due to the inclusion of ferrocene, Fc became hydrophilic and is oxidized into charged Fc+, leading to disassembly and fluorescence recovery, which can be used to construct the fluorescent sensing system for detecting biomolecular substrates. Furthermore, based on its high sensitivity to oxidizing molecules and electrical stimulation, we evaluated its application potential as a drug delivery system and believe that this system has significance for advancing the development of fluorescent polymers in the field of medicine.