From Glycine to Porphyrin: How to Make Carbon Polymer Dots with Effective Photoinduced Virucidal Activity

Porphyrins are well-known photosensitizers with applications in photodynamic treatments for oncology and antimicrobial therapies, mainly due to their high singlet oxygen (1O2) quantum yield. However, challenges such as poor water solubility and complex multi-step synthetic procedure still hinder their clinical development. This study presents an innovative one-pot method for the synthesis of water-soluble and red-emitting porphyrin virucidal photosensitizers in the form of carbon polymer dots by direct thermal processing of glycine. We have made a significant stride by extending glycine condensation beyond the traditional formation of polypeptides, now achieving the remarkable generation and self-assembly of porphyrin derivatives within a carbonized polymeric matrix. The resultant “porphyrin-like dots” exhibit high water solubility, biocompatibility, strong photoluminescence and efficient 1O2 generation, as demonstrated by Indocyanine Green photodegradation tests. Notably, the dots also displayed significant photoinduced virucidal activity against Vaccinia virus, with up to 92 % inactivation at the highest concentration. These findings propose the produced porphyrin-like dots as promising theranostic tools for biomedical applications, combining potential diagnostic imaging and therapeutics functions.