Photo-crosslinked composite hydrogels with silver-deposited polymeric carbon nitride for boosting antibacterial activity

Rational design of antibacterial hydrogels is an important link to promote the multi-scenario application of this promising soft material. Herein, acrylamide and sodium alginate were selected as mixed monomers, silver deposited polymeric carbon nitride nanosheets were used as a photoinitiator, pre-gelation was achieved under UV irradiation, and then a composite hydrogel was obtained through calcium ion crosslinking. The composite hydrogels exhibit good mechanical stability, structural stability in water and degradability under simulated physiological conditions. The composite hydrogels have the activity of killing Escherichia coli with or without light. The visible light response and surface plasmon resonance effect of the silver-deposited polymeric carbon nitride boosted the photocatalytic antibacterial activity of the composite hydrogels, and the bactericidal rate of the optimal sample reached 95.5% after 120 min of visible light irradiation. This work provides a constructive and green roadmap for the design of composite dual-network photoresponsive antibacterial hydrogels.