Poly[2-(3-thienyl)ethyloxy-4-butylsulfonate] sodium salt

López Cabarcos, E., and Sue A. Carter. Macromolecules 38.25 (2005): 10537-10541.

Poly[2-(3thienyl)ethoxy-4-butylsulfonic acid] sodium salt (PTE-BS) is a water-soluble luminescent conjugated polymer. The photoluminescence of PTE-BS can be quenched by using low concentrations of methylviologen (MV), and this effect can be used to develop its application in biosensors for ultra-analytical technologies. It is important to understand how the molecular weight of the polymer and the ionic strength of the medium affect photoluminescence, as these parameters may determine the yield and stability of the final biosensor product.
Poly[2-(3-thienyl)ethoxy-4-butylsulfonic acid] sodium salt with M ≈ 10^6 and M ≈ 5 × 10^3 to prepare aqueous polymer solution,
And PL and absorption measurements were performed according to previously reported methods. A polymer stock solution with a concentration of 1.89 × 10^-3M is usually prepared and then purged with nitrogen for more than 3 hours to prepare the solution for fluorescence and absorption spectrum measurements to 1.89 × 10^-4M. Adjust the ionic strength of the solution to a given value by adding the required amount of salt. Before taking PL measurements, the solution was stirred for approximately 3 min and a new amount of salt was added. Experiments were performed at room temperature (approximately 23°C). Results and Discussion Effect of molecular weight on photoluminescence of PTE-BS. As the molecular weight of the polymer increases, both the absorption and fluorescence broad maxima move toward higher wavelengths. A red shift of the absorption maximum from 405 nm to 425 nm and a red shift of the fluorescence maximum from 512 nm to 557 nm can be observed.