{"title":"Characterization, antioxidant activity of banana peel carbon dots and their antibacterial mechanism against Staphylococcus aureus.","authors":"Kai Fan, Rui Tang, Lijing Li","doi":"10.1093/jambio/lxaf163","DOIUrl":null,"url":null,"abstract":"<p><strong>Aims: </strong>The carbon dots (CDs) used in this study are a type of carbon nanomaterial extracted from banana peels, which possess various biological activities and demonstrate significant advantages in the antimicrobial field. Staphylococcus aureus (S. aureus) is one of the most common foodborne pathogenic bacteria, severely impacting human health and food safety, as well as causing substantial economic losses. This study investigates the properties of the CDs and their inhibition mechanism against S. aureus.</p><p><strong>Methods and results: </strong>The synthesized CDs were characterized using transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), fluorescence spectroscopy, X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The antioxidant activity and antimicrobial effect of CDs were explored through free radical scavenging and bacterial experiments. The cytocompatibility of CDs was determined by MTT assay. The results showed that spherical blue CDs of 6.4 ± 1.56 nm were synthesized. CDs showed a UV-visible absorption peak at 265 nm. CDs are rich in hydroxyl, carboxyl, and amino groups, demonstrating excellent water solubility, photostability, pH stability, and antioxidant properties. The findings showed that CDs disrupt the cell membrane structure of S. aureus, resulting in altered membrane permeability, leakage of cell contents, and accumulation of excessive ROS. The minimum inhibitory concentration (MIC) was found to be 3.125 mg mL-1. Moreover, the CDs exhibited good cell compatibility.</p><p><strong>Conclusion: </strong>CDs are an ideal antioxidant and natural antibacterial agent that can inhibit S. aureus. The antioxidant effect of CDs is achieved through radical scavenging, and they exhibit good cytocompatibility. At the same time, CDs exhibits strong antifungal activity through mechanisms such as disrupting the cell membrane structure, altering membrane permeability, causing leakage of cellular contents, increasing MDA levels, and accumulating intracellular ROS.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2000,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Microbiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1093/jambio/lxaf163","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Aims: The carbon dots (CDs) used in this study are a type of carbon nanomaterial extracted from banana peels, which possess various biological activities and demonstrate significant advantages in the antimicrobial field. Staphylococcus aureus (S. aureus) is one of the most common foodborne pathogenic bacteria, severely impacting human health and food safety, as well as causing substantial economic losses. This study investigates the properties of the CDs and their inhibition mechanism against S. aureus.
Methods and results: The synthesized CDs were characterized using transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), fluorescence spectroscopy, X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The antioxidant activity and antimicrobial effect of CDs were explored through free radical scavenging and bacterial experiments. The cytocompatibility of CDs was determined by MTT assay. The results showed that spherical blue CDs of 6.4 ± 1.56 nm were synthesized. CDs showed a UV-visible absorption peak at 265 nm. CDs are rich in hydroxyl, carboxyl, and amino groups, demonstrating excellent water solubility, photostability, pH stability, and antioxidant properties. The findings showed that CDs disrupt the cell membrane structure of S. aureus, resulting in altered membrane permeability, leakage of cell contents, and accumulation of excessive ROS. The minimum inhibitory concentration (MIC) was found to be 3.125 mg mL-1. Moreover, the CDs exhibited good cell compatibility.
Conclusion: CDs are an ideal antioxidant and natural antibacterial agent that can inhibit S. aureus. The antioxidant effect of CDs is achieved through radical scavenging, and they exhibit good cytocompatibility. At the same time, CDs exhibits strong antifungal activity through mechanisms such as disrupting the cell membrane structure, altering membrane permeability, causing leakage of cellular contents, increasing MDA levels, and accumulating intracellular ROS.
期刊介绍:
Journal of & Letters in Applied Microbiology are two of the flagship research journals of the Society for Applied Microbiology (SfAM). For more than 75 years they have been publishing top quality research and reviews in the broad field of applied microbiology. The journals are provided to all SfAM members as well as having a global online readership totalling more than 500,000 downloads per year in more than 200 countries. Submitting authors can expect fast decision and publication times, averaging 33 days to first decision and 34 days from acceptance to online publication. There are no page charges.