Emerging tetrapyrrole porous organic polymers for chemosensing applications

Chemosensors are of great significance for medical detection, food safety, and environmental monitoring, and have received more and more attention. Tetrapyrrole porous organic polymers (POPs), as promising materials, were concerned widely due to their adjustable pore sizes, structures, and functions. Furthermore, the permanent porous nature of tetrapyrrole POPs can provide abundant adsorption sites to pre-enrich the guest molecules and facilitate the interaction between tetrapyrrole POPs and guest molecules, making tetrapyrrole POPs attractive for chemosensing applications. Here, we provide a comprehensive overview of tetrapyrrole POPs as chemosensing platforms. The chemosensors based on tetrapyrrole POPs fall into six main categories: electrochemical sensors, photoelectrochemical sensors, colorimetric sensors, fluorescence sensors, chemiresistive sensors, and quartz crystal microbalance sensors. And the various sensing applications of these six types of chemosensors in the detection of small molecules, biological molecules, heavy metal cations, anions, and toxic gas are summarized. The synthetic strategies of tetrapyrrole POPs with different structures and the related sensing mechanisms are also discussed. Finally, a brief exposition of the future perspectives is concluded.