Bacterial Detection and Elimination Using a Dual-Functional Porphyrin-Based Porous Organic Polymer with Peroxidase-Like and High Near-Infrared-Light-Enhanced Antibacterial Activity

The efficient fabrication of multifunctional nanoplatforms for bacterial detection and elimination is of great importance in nanobiotechnology. A new porphyrin-based porous organic polymer, FePPOPBFPB, was synthesized via the reaction between pyrrole and 4-{2,2-bis[(4-formylphenoxy)methyl]-3-(4-formylphenoxy) propoxy} benzaldehyde (BFPB). The C-centric tetrahedral structure of BFPB promoted the formation of FePPOPBFPB with a 3D interconnected porous structure, high specific surface area, and plentiful surface catalytic active sites. The adjustable structural alkyl chain also enhanced the absorption capability of FePPOPBFPB in the long-wavelength visible and near-infrared regions (NIR). FePPOPBFPB exhibited excellent peroxidase-like activity toward a representative peroxidase substrate, 3,3′,5,5′-tetramethylbenzidine (TMB) with H2O2. Utilizing these features, a rapid and visual detection of Staphylococcus aureus (S. aureus) based on FePPOPBFPB was established and exhibited high sensitivity and stability. Combining the catalysis with near-infrared-light (NIR) absorption, FePPOPBFPB can effectively catalyze the decomposition of biologically relevant concentrations of H2O2 to produce vast amounts of •OH radicals via the photo-Fenton reaction, which avoids the utilization of high toxic concentrations of H2O2. On the basis of these satisfactory features, FePPOPBFPB had a conspicuous bactericidal performance against S. aureus under NIR irradiation. To our knowledge, this is the first example of a porphyrin-based porous organic polymer antibacterial agent. The main reactive oxygen species (ROS) produced in this system and the possible antibacterial mechanism of FePPOPBFPB was also proposed through a series of experiments.