The increased mortality caused by pathogenic
bacterial infection calls for early
infection diagnosis and effective
antibiotic alternatives. In this work, we developed a fluorescent nano-probe named ZnO@PEP-MPA by conjugating BSA-stabilized ZnO
quantum dot (ZnO@BSA) with UBI29-41, an anti-bacteria
peptide fragment, and MPA, a near infrared (NIR)
dye. The nanoprobe ZnO@PEP-MPA exhibited low cytotoxicity and could discriminate the
bacterial infection from sterile
inflammation or
cancer in vivo with high specificity and low detection limitation. Based on the platform of ZnO@PEP-MPA, a
theranostic nanocomposite, Van@ZnO-PEP-MPA was firstly established by further decorating ZnO@PEP-MPA with
Vancomycin, a kind of
glycopeptide antibiotic, which demonstrated enhanced antibacterial activity and desirable biocompatibility both in vitro and in vivo. Furthermore, another
antibiotic methicillin was immobilized onto ZnO@PEP-MPA, forming Met@ZnO-PEP-MPA and demonstrated significant improved capability to combat with the anti-methicillin-resistant-bacteria in comparison with free
methicillin as a result of the increased cell membrane permeation mediated by ZnO@BSA-PEP-MPA. Therefore, ZnO-PEP-MPA reported in this work holds promising potential to realize efficient non-invasive diagnosis of
bacterial infections, providing important guiding information for treatment, and can be employed as
drug carriers for effective bacterial-targeting
therapy, favorable to hurdle multi-drug resistance after being loaded with
antibiotics.