Pillar[5]arene stabilized gold nanoparticles for the enhanced light-triggered nitric oxide release with antibacterial and antibiofilm activities

The reactivity of guests confined in well-defined host cavities act significantly different from that in bulk systems. In this work, pillar[5]arene not only works as a stabilizer for the fabrication of gold nanoparticles , but also act as an accelerator for the enhanced photo-triggered release of gaseous nitric oxide (NO) from encapsulated NO donor . The host–guest complex can dramatically improve the photoactivity of loaded guest molecule to generate antibacterial NO molecules through the confinement effect of pillar[5]arene cavity. The synergistic photo-triggered localized NO release and photo-thermal effect of host–guest complex demonstrated impressive antibacterial behaviors against Gram-negative bacterial strain Escherichia coli , Gram-positive bacterial strain Staphylococcus aureus and methicillin-resistant Staphylococcus aureus . Moreover, this biocompatible photo-responsive complex can also inhibit bacterial biofilm formation and disrupt the pre-existing biofilms. • Pillar[5]arene with intrinsic cavity and specific host–guest recognitions was explored as a stabilizer for the fabrication of gold nanoparticles and an accelerator to enhance the photo-triggered release of gaseous nitric oxide (NO) from encapsulated NO donor in the host–guest complex. • Pillar[5]arene anchored on the surface of gold nanoparticles can significantly improve the photoactivity of encapsulated guest molecule owing to the confinement effect of the well-defined cavity, providing a facile and universal chemical pathway to modulate molecule reactivity. • This host–guest complex with synergistic photo-triggered localized NO release and photo-thermal effect demonstrates impressive antibacterial and antibiofilm activity against Gram-negative, Gram-positive and drug-resistant bacterial strains. • This study fully highlights the potentialities of supramolecular macrocycles in mimicking the high catalytic activity and substrate selectivity of enzymes by utilization of supramolecular macrocycles.