Preparation And Photothermal Antibacterial Properties Of Graphdiyne-based Composites

Due to the abuse of antibiotics,the emergence of drug-resistant bacteria weakens the effectiveness of traditional anti-infection treatment,and bacterial infection has become one of the biggest threats to human health.Therefore,there is an urgent need to develop new anti-infective therapies.Over the past few decades,several anti-infection treatments have been developed that do not rely on antibiotics,such as antimicrobial therapy based on bioactive materials,photodynamic therapy(PDT),and photothermal therapy(PTT).Among these approaches,PTT is showing increasing potential in the treatment of bacterial infections.Photothermal agents(PTA)can convert light energy into heat energy,resulting in membrane rupture,protein denaturation and irreversible bacterial damage.Graphdiyne(GDY),as a new carbon allotrope,has attracted extensive research in biomedical fields due to its semiconductor properties,excellent photothermal conversion ability and unique structure.In this paper,GDY loaded gold-silver nanocages(AuAg/GDY@PEG),goldsilver nanocages loaded nitrogen doped GDY quantum dots(N-GDQDs/AuAg)and graphdiyne/graphene-loaded manganese atoms heterostructures(Mn/GDY/G)were prepared.Their antibacterial properties under near infrared(NIR)laser irradiation were studied.The main research contents are as follows:1.We prepared a biocompatible AuAg/GDY@PEG composite.The combination of AuAg and GDY to obtain a synergistically enhanced photothermal effect,and the antibacterial effect of GDY and AuAg were used in combined anti-infective therapy.The in vitro antibacterial activity of AuAg/GDY@PEG was investigated,which showed an impressive broad-spectrum antibacterial activity with the killing rate>99.999%.Based on the photothermal conversion ability of AuAg/GDY@PEG,a simple photothermal immunoassay for pathogenic bacteria was successfully established.Sandwich immune response was performed on a microporous plate,the microplate containing the antibody binds specifically to the bacterium being tested,which then binds to the material with the antibody on its surface,and the change in temperature under 808 nm NIR light as detection signal.2.N-GDQDs/AuAg heterostructures nanozyme were prepared with strong local surface plasmon resonance(LSPR)response in the NIR region.This nanozyme can concurrently harvest LSPR-induced hot carriers and produce photothermal effects,resulting in a significantly enhanced peroxidase-like activity upon 808 nm irradiation.Both experimental data and theoretical calculations revealed that the remarkable catalytic performance of N-GDQDs/AuAg results from the narrow band gap semiconductor characteristics of N-GDQDs,LSPR effect of AuAg,and fast interfacial electron transfer dynamics.Moreover,this nanozyme is demonstrated to achieve>99.999% antibacterial efficiency against methicillin-resistant MRSA,S.aureus,and E.coli in 10 min in vitro and in vivo.3.The GDY/G heterostructure was synthesized by growing thin layers of GDY on the surface of monolayer graphene,it showed with good photothermal conversion and conductivity.Then Mn atoms with peroxidase activity were loaded on the surface of GDY/G to prepare Mn/GDY/G antibacterial materials with photothermal and peroxidase properties.The high specific surface area and abundant anchor sites of GDY promoted the uniform distribution of Mn atoms and increased the number of active sites.By combining heat with ROS,it showed an antibacterial efficiency of>99.999% against S.aureus and E.coli.