Paper-based smartphone chemosensor for reflectometric on-site total polyphenols quantification in olive oil

•A paper-based chemosensor with smartphone reflectometry detection relying on the F C assay was developed for direct total polyphenols analysis.•3D printing and PDMS replica molding technologies were used to develop all-in-one analytical device for on-site polyphenols quantification.•The chemosensor has been applied to measure polyphenols in extra virgin olive oil and aqueous food matrices.