聚噻吩（Polythiophene，缩写PT）是噻吩聚合生成的高分子化合物。在通过掺杂向其共轭的π轨道引入或去除电子时，它可转变为导体。因此聚噻吩及其类似物是近些年的研究热门课题，2000年诺贝尔化学奖即是颁给研究这一主题的艾伦·黑格、艾伦·麦克德尔米德和白川英树。

导电性是这些化合物最重要的性质，是由电子在聚合物主链上离域而产生。除了导电性以外，聚噻吩还有奇特的光学性质。在溶剂、温度、电位和其他分子等环境因素影响下，聚噻吩主链发生扭转，共轭结构被破坏，致使其迅速发生颜色的转变。上述特殊的电学和光学性质使聚噻吩和类似的共轭聚合物有作为传感器的潜在应用。

Polythiophenes (PTs) are polymerized thiophenes, a sulfur heterocycle. They can become conducting when electrons are added or removed from the conjugated π-orbitals via doping.

The study of polythiophenes has intensified over the last three decades. The maturation of the field of conducting polymers was confirmed by the awarding of the 2000 Nobel Prize in Chemistry to Alan J. Heeger, Alan MacDiarmid, and Hideki Shirakawa "for the discovery and development of conductive polymers". The most notable property of these materials, electrical conductivity, results from the delocalization of electrons along the polymer backbone – hence the term "synthetic metals". However, conductivity is not the only interesting property resulting from electron delocalization. The optical properties of these materials respond to environmental stimuli, with dramatic color shifts in response to changes in solvent, temperature, applied potential, and binding to other molecules. Both color changes and conductivity changes are induced by the same mechanism—twisting of the polymer backbone, disrupting conjugation—making conjugated polymers attractive as sensors that can provide a range of optical and electronic responses.