Paper microzone plates integrating Natural Deep Eutectic Solvents: Total phenolic compounds and antioxidant capacity as performed by nature

Abstract

Determination of total phenolic content and antioxidant capacity are routine and essential tasks for plant and food characterization that have been carried out by traditional spectrophotometric approaches, which are time consuming and use large amounts of solvents. Herein we propose a portable system aligned with the principles of Green Analytical Chemistry for total phenolic content and antioxidant capacity determination in Natural Deep Eutectic Solvent media. These green solvents have been proposed as a third cellular media, so monitoring metabolic reactions in NADES represents a revolutionary approach in the field of biomimetic. A NADES mediated paper microzone via a smartphone camera methodology was developed and applied to characterize extracts from medicinal plants. The method was successfully validated against traditional assays with correlations higher than 80%. In order to establish the greenness profile of the proposed methodologies, the “Green Certificate” was applied and compared with traditional techniques. The proposed approach reduced more than 22 times the Penalty Points with a Green Certificate of 99.525.