An Electropolymerization (EP)-based Fluorescent Film Probe to Fe³⁺ Using Conjugated Polymer as Precursor

A conjugated polymer P-M2 with carbazole units as impendent sidechains is used as the electropolymerization (EP) precursor to prepare EP film and realize the coupling reaction between conjugated polymers. Further, the EP film is used as the fluorescent film probe to Fe³⁺, whose limit of detection (LOD) is calculated to be 1.4×10⁻⁷ mol/L. Compared with that of the EP film prepared by small molecule precursor M2, the LOD is enhanced ten times. The results are due to both the long conjugation length of P-M2 and the inherent highly cross-linking network microstructures of P-M2 EP film. Hereby, this work realizes not only the reaction between conjugated polymers but also a new precursor for the EP method and a promising fluorescent film sensor candidate.