High specificity ZnO quantum dots for diagnosis and treatment in bacterial infection

Abstract

Early diagnosis and effective treatment of bacterial infection has become increasingly important. Herein, we developed a fluorescent nano-probe MPA@ZnO-PEP by conjugating SiO2-stabilized ZnO quantum dot (ZnO@SiO2) with bacteria-targeting peptide PEP, which was encapsulated with MPA, a near infrared (NIR) dye. The nanoprobe MPA@ZnO-PEP showed excellent fluorescence property and could specifically distinguish bacterial infection from sterile inflammation both in vitro and in vivo. The favorable biocompatability of MPA@ZnO-PEP was verified by MTT assay. This probe was further modified with antibiotic methicillin to form the theranostic nanoparticle MPA/Met@ZnO-PEP with amplified antibacterial activity. These results promised the great potential of MPA@ZnO-PEP for efficient non-invasive early diagnosis of bacterial infections and effective bacterial-targeting therapy.