Photoresponsive Nanoarchitectonics Based on Copper-Porphyrins for Near-Infrared-Enhanced Bacterial Treatment.

Antibiotic resistance is one of the biggest challenges that causes incurable diseases and endangers public health. Metal-porphyrin-modified nanoarchitectonics can enhance the bacterial affinity and destruction of cell walls. Herein, a new photoresponsive nanoarchitectonics (BPGa@COF-Cu) was synthesized by doping Ga(III) on the surface of black phosphorus (BP) and subsequently loaded into a Cu(II)-based covalent-organic framework (COF-Cu). The COF-Cu was induced by the coupling reaction of terephthalic chloride with amino-substituted porphyrin derivatives (THPP), followed by the coordination of the Cu(II) ion. The material BPGa@COF-Cu is a nanoball, and the mean radius is ca. 250 nm. The photochemical properties of BPGa@COF-Cu show that it efficiently catalyzes H2O2 into ·OH. BPGa@COF-Cu can also produce both singlet oxygen and heat upon 808 nm irradiation. Further, BPGa@COF-Cu was employed to inhibit bacteria, and the results showed that it can destroy the membrane of bacteria. The MIC (minimal inhibition concentration) of BPGa@COF-Cu against E. coli was 1 µg/mL. All the data suggest that BPGa@COF-Cu is a multiple nanoarchitectonics for bacterial treatment.

Europium- and Black Phosphorus-Functionalized Porphyrin as an l-Arginine Sensor and l-Arginine-Activated PDT/PTT Agent for Bacterial Treatment.

The attenuation of bacterial metabolism provides an adjunct to the treatment of bacterial infections. To develop a bacterial eradication agent, a bioactivatable material (BP@Eu-TCPP) was designed and synthesized by coordination and reduction of europium(III) with thin-layer black phosphorus (BP) and tetrakis (4-carboxyphenyl) porphyrin (TCPP). The existence of the P-Eu bond and Eu2+ 3d5/2 in X-ray photoelectron spectroscopy confirmed the successful synthesis of BP@Eu-TCPP. This material showed high fluorescence sensitivity to l-Arginine (l-Arg) and the main binding ratio of BP@Eu-TCPP to l-Arg was ca. 1:2 or 1:3, with the limit of detection of 4.0 µM. The material also showed good photothermal properties and stability, with a photothermal conversion efficiency of 37.3%. Although metal coordination has blocked the generation of 1O2, the addition of l-Arg to BP@Eu-TCPP can restore 1O2 generation upon red light-emitting diode (LED) light irradiation due to the formation of water-soluble Arg-TCPP species. Additionally, BP@Eu-TCPP was enabled to change the bacterial membrane and interfered with the bacterial iron absorption that effectively contributes to bacterial eradication. Such BP@Eu-TCPP is promised to be a novel material for the detection of l-Arg and l-Arg-activated photodynamic therapy.