Biological assessment of synthesized carbon dots from polyphenol enriched extract of pomegranate peel, incorporated with Mentha piperita essential oil

Abstract

Carbon dots (CDs) have attracted the attention of many researchers in terms of their extraordinary properties as a new and progressive science in nanomedicine. Pomegranate peel is an agricultural waste due to its chemical feature and diverse bioactive compounds with many health benefits. This work used a polyphenol-enriched pomegranate peel extract (PPE) as a precursor to synthesize CDs by a one-pot hydrothermal process. M. piperita essential oil (MEO) as a drug model loaded on CDs with the hydrothermal method. In addition, organic additives such as ethylene diamine, urea, and citric acid were used to adjust the fluorescence emission. Acquired carbon dots were characterized using UV–Vis, ATR-FTIR, PL, DLS, FESEM, HRTEM, EDAX, and Zeta potential analysis. Hence, the prepared carbon dots’ biological efficiency was studied via various in vitro tests, for instance, antioxidant, antibacterial, and cytotoxicity assays. The Korsmeyer- Peppas kinetic model governed the release behavior of CDs and CDs/MEO. The experiment confirmed that carbon dots (CDs, CDs/MEO) distributing the desired and uniform sizes of 6.1 ± 1.2 nm and 33.09 ± 5.1, respectively, exhibited bright blue color with a quantum yield of 20.51% and 17. 50% belongs to CDs and CDs/MEO, respectively. The developed CDs and CDs/MEO were tested for in brine shrimp assay and no toxicity was observed. Furthermore, the Gram-positive bacteria staphylococcus aureus was eradicated by CDs/MEO with a minimum inhibition concentration (MIC) of 0.31 mg ml−1. Antioxidant scavenging activity was investigated in the DPPH assay. Moreover, CDs with IC50 = 22.18 μg ml−1 have more antioxidant activity. Indeed, the results show obvious enhanced antioxidant and antibacterial activity, which opens a new way for extensive applications of carbon dots.