Conjugated polyelectrolytes as fluorescent sensors

Conjugated polyelectrolytes (CPEs) have become one of the most utilized materials in chemo- and bio-sensory systems. Useful properties of CPEs, such as amplified quenching effects and aggregation behavior, are illustrated in detail in order to provide guidelines for underlying concepts of CPE-based sensors. Well established sensing mechanisms, such as conformational changes and fluorescence resonance energy transfer, are reviewed with representative examples. Target species include small ions, small biomolecules, proteins, enzymatic activities, and DNA. New and unique mechanisms for CPE-based sensing are also described.