Conjugated Polythiophene/Porphyrin Complex for Rapid and Simple Detection of Bacteria in Drinking Water

摘要

An electrostatic complex combining anionic water-soluble conjugated polythiophene (PTP) with commercial cationic porphyrin (5,10,15,20-tetrakis(4-(trimethylammonio)-phenyl)-21H,23H-porphine tetratosylate (TMP)) has been designed for rapid and simple detection of bacteria infection in drinking water by applying fluorescence resonance energy transfer (FRET) strategy. There is efficient FRET from PTP to TMP for the electrostatic complex of PTP/TMP. Upon the addition of bacteria, the cationic TMP is adsorbed tightly to the negatively charged membrane surface of bacteria through electrostatic interactions, making the PTP reside in much farther proximity to TMP than that in the absence of bacteria. Therefore, much weaker FRET is observed. Interesting, the detection for bacteria based on FRET changes of PTP/TMP complex is visual in view of the color changes under ultraviolet (UV) irradiation. This assay takes advantage of the light-harvesting property of conjugated polymer and the ratiometric measurements for minimizing the nonspecific binding effect. The strategy is promising in pathogen detection in drinking water and other sources.