Antibacterial 3D graphene composite gel with polyaspartamide and tannic acid containing in situ generated Ag nanoparticle

The increased use of medical devices combined with the emergence of new multi‐drug‐resistant bacteria has enhanced research on biomaterial‐related infections. Small size of Ag nanoparticles (AgNPs) has already been suggested to show high antibacterial activities. However, small AgNPs tend to aggregate during preparation, resulting in a significant decrease in their antibacterial properties. Three‐dimensional (3D) graphene can be used as a support matrix, for the fixation of precious metal NPs and the maximization of the load. Here, we present a synthetic poly(amino acid), specifically, polyaspartamide modified by ethylenediamine and ethanolamine [PolyAspAm(EDA/EA)], which was mixed with tannic acid and graphene oxide to fabricate an ultralight 3D graphene hybrid aerogel. Transmission electron microscopy (TEM) revealed AgNP loading on the aerogel with the size of less than 50 nm uniformly dispersed, and AgNP loading on the aerogels led to the inhibition of antibacterial cell growth. The measured antibacterial activity, as determined by the inhibition zone and optical density in test, demonstrated that PolyAspAm(EA/EDA)/TA‐GO‐AgNP has a bacteriostatic and bactericidal effect against Staphylococcus aureus and Escherichia coli, thereby suggesting that this 3D polymer graphene composite gel has potential as a novel antibacterial material for a wide range of clinical applications.