Construction Of Supramolecular Nanoassembly For Responsive Antibacterial Elimination And Effective Bacterial Detection

The globally growing bacterial infection has severely affected human health.The bacterial infection is related to many aspects such as medical devices,food packing and daily supplies.The emergence of antibiotic resistance caused by the misuse of antibiotics further aggravated the infected situation.World Health Organization（WHO）experts indicated that some measures should be taken to slow the emergence of multi-resistant bacteria.Firstly,the crucial way to achieve this goal is to diagnose accurately and then inform proper treatment with minimal disease spread.Theranostic system that combines diagnostic ability and therapeutic effect has been paid extensive attention due to their excellent features such as high efficiency,real-time performance and low resistance.Therefore,the progress of antibacterial agents including natural antibacterial compounds,quaternary ammonium polymer,and inorganic nanoparticles with dual function of detection and imaging was introduced.Multiple imaging modal based on molecular diagnostics,optical methods,and some functional nanoparticles,antibacterial modal were discussed for better understanding of the development of theranostics.We summarize the current situation and limitations of multifunctional antimicrobial agents,and provides theoretical basis for optimization and development of antimicrobial materials.There is an urgent need for developing novel strategies for bacterial detection and inhibition.Herein,a multifunctional nanomaterial based on mesoporous silica nanoparticles（MSNs）is designed,loaded with amoxicillin（AMO）,and surface-coated with1,2-ethanediamine（EDA）-modified polyglycerol methacrylate（PGEDA）,cucurbit[7]uril（CB[7]）,and tetraphenylethylene carboxylate derivatives（TPE-（COOH）₄）.When bacteria contacts with this nanoassembly,the binding of anionic bacterial surface toward the cationic PGEDA layer of this material can reduce or break the interactions between PGEDA layer and TPE-（COOH）₄ layer,leading to attenuated TPE-（COOH）₄ emission due to the weakening of aggregation-induced emission（AIE）effect.Furthermore,upon adding adamantaneamine（AD）,the more stable AD&CB[7]complex forms and PGEDA is liberated through competitive replacement,thus leading to the release of AMO and resulting in much higher antibacterial ability of this nanomaterial.This newly designed nanomaterial possesses dual functions of controllable antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli,and bacterial detection ability in aqueous media,suggesting that the design of this multifunctional antibacterial material will provide a simple,efficient way to control the activity of antimicrobial and open up an alternative new avenue for bacterial detection and elimination.