Controlling the photoluminescence of water‐soluble conjugated poly[2‐(3‐thienyl)ethyloxy‐4‐butylsulfonate)] for biosensor applications

The photoluminescence of poly[2‐(3‐thienyl)ethyloxy‐4‐butylsulfonate)] (PTE‐BS) in aqueous solution increases threefold on addition of the surfactant tetrabutylammonium perchlorate (TBA). Furthermore, the luminescence of the PTE‐BS/TBA system is reduced by more than five times by the addition of small amounts of the cationic electron acceptor methyl viologen (MV 2+ ). The Stern–Volmer constant K SV = 1.4 × 10 4 L mol −1 for the quenching of the polymer–surfactant complex by MV 2+ is approximately 60 times smaller than the K SV = 8.4 × 10 5 L mol −1 obtained in water polymer solutions without surfactant. Thus, the luminescence of PTE‐BS in aqueous solution can be modulated by complexing the polymer either with a surfactant or with a quencher. In this contribution we show that the surfactant/quencher tuning effect found in polymers of the phenylenevinylene family, such as poly(2,5‐methoxy‐propyloxysulfonate phenylenevinylene), also appears in polymers of the thiophene family such as PTE‐BS. Copyright © 2007 Society of Chemical Industry