Properties of Ophioglossum vulgatum L. extract Pickering emulsion stabilized by carbon dots and its potential use in cosmetics

Ophioglossum vulgatum L. (O. vulgatum) is a species of fern used in traditional Chinese medicine, however, its application in cosmetics has not yet been studied. This study obtained O. vulgatum extract using 70% ethanol solution and evaporation. Fourier Transform Infrared Spectrometer (FTIR) analysis identified many active components in O. vulgatum extract, such as polyols, amino acids, and flavonoids. A Pickering emulsion of O. vulgatum extract was also prepared, stabilized by a type of carbon dot based on l-arginine (CDs-Arg). The prepared Pickering emulsion was characterized by metallographic microscope and contact angle measurement. The results demonstrated that it was a pH-responsive O/W emulsion. Facial cleanser was then created using the prepared Pickering emulsion as the main component. When squeezed onto hands, the cleanser produced many delicate foams and caused no skin irritation. The prepared Pickering emulsion facilitated the use of O. vulgatum in facial cleanser.