Porphyrin doped europium/black phosphorus nanoarchitectonics as the sensor of L-arginine and gram-negative bacteria

The L-arginine (L-Arg) in Escherichia coli (E. coli) is associated with the biofilm formation and drug resistance evolution. The detection of L-Arg and E. coli is meaningful to the control of pathogen infection. Herein, porphyrin modified europium black phosphorus (BP) nanoarchitectonics (labelled as BPEu@TAC) was synthesized and characterized by a variety of spectroscopic methods. The existence of Eu(II/III)-BP was confirmed by XPS data and Raman spectra. It was found that L-Arg can turn on the emission at 548 nm of BPEu@TAC with a visual color change, while other amino acids showed less effect. The detection limit of L-Arg is ca. 2.02 μM. In particular, the fluorescence response of BPEu@TAC to bacteria is related to the concentration of L-Arg. BPEu@TAC + L-Arg system was more sensitive to E. coli than S. aurus. The fluorescence emission change of BPEu@TAC + L-Arg system is affected by the concentration of E. coli. Therefore, BPEu@TAC can sense the level of L-Arg and the metabolism of L-Arg in E. coli.