Single-Molecule Resolution of Oligopeptides in Anti-Aging Cosmetics Combined with Nanopore Readouts and Deep Learning Model

Oligopeptides in anti-aging cosmetics stand out as active ingredients to interact with skin cell and accelerate the collagen synthesis and fibroblast proliferation. Some of them act as neurotransmitter- or enzyme inhibitor, while others are signal or carrier peptides. The ensemble techniques for the extraction and analysis of the bioactive peptides in cosmetic production involve ultrafiltration, enzymatic hydrolysis, fermentation, and high-performance liquid chromatography. This work provides a single-molecule approach for the resolution of various typical oligopeptides in anti-aging cosmetics. A nanopore with an aperture diameter of ~ 2 nm is efficient for the shortest tripeptide to achieve good signal to noise ratio and translocation frequency. Oligoeptides with three to eight amino acids could be discriminated with a ~ 2 nm single SiN _x nanopore, this is also proved by AI modeling with an accuracy of ~ 90%, except the argireline and hexa-peptide-9 that hold similar translocation behavior in KCl. The assay for the argireline in three commercial anti-aging cosmetics reveals that the product from Viribati is purer than the other two and harbors the majority of argireline according to the comparison setups in a single nanopore device. Our work provides a significant insight in the qualification and quality control in anti-aging cosmetic market.