Regulation of luminescence band and exploration of antibacterial activity of a nanohybrid composed of fluorophore-phenothiazine nanoribbons dispersed with Ag nanoparticles

Abstract

A D–π–A type phenothiazine derivative 4-((E)-2-(10-ethyl-10H-phenothiazin-3-yl)-vinyl)-benzaldehyde (abbreviated as L) was designed, synthesized and characterized by single crystal X-ray diffraction analysis. Dispersion-corrected theoretical calculation revealed that L molecules tend to grow along a 1-dimensional (1-D) orientation. Further, L was used to prepare nanohybrids consisting of silver nanoparticles (NPs) dispersed on L nanoribbons. L molecules coupled with Ag NPs through S atoms, which brought about a significant blue-shift of the fluorescence (FL) and an obvious increase of FL lifetime. Through fluorescence microscopy, the spectral change was used as a wavelength-based biodetection tool to study the possible mechanism for an enhanced inhibitory effect of L–Ag nanohybrids on both gram-negative bacterium Escherichia coli and gram-positive bacterium Staphylococcus aureus compared to either pure Ag NPs or pure L.