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 (MV2+). The Stern-Volmer constant K-SV = 1.4 x 10(4) L mol(-1) for the quenching of the polymer-surfactant complex by MV2+, is approximately 60 times smaller than the K-SV = 8.4 x 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. 2007 Society of Chemical Industry.