Gold nanoparticles decorated graphene oxide/nanocellulose paper for NIR laser-induced photothermal ablation of pathogenic bacteria

A functionalized paper based on gold nanoparticles (Au NPs) conjugated graphene oxide (GO) was developed for near-infrared (NIR) laser triggered photothermal ablation against infectious bacterial pathogens. Firstly, quaternized carboxymethyl chitosan (QCMC) not only acted as reducing agent to synthesize Au NPs, but also functioned as coupling agent to link up Au NPs with GO. Au-QCMC-GO(+) was supposed to synergistically intensify the photothermal effect, which was then mixed with nanocellulose to form a functionalized paper via vacuum filtration. The photothermal efficiency, antibacterial treatment and mechanical property of Au-QCMC-GO(+)/nanocellulose paper were investigated. Excited by NIR laser irradiation, Au-QCMC-GO(+)/nanocellulose paper generated a temperature rise over 80 °C, sufficient for photothermal ablation upon both Gram-positive bacteria (Bacillus subtilis and Stapylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Additionally, Au-QCMC-GO(+)/nanocellulose paper showed a remarkable enhancement in tensile strength, bursting index and tear index compared to those of pure nanocellulose paper.