The Dualex is an optical sensor used in plant science and agriculture for the assessment of flavonol, anthocyanin, and chlorophyll contents in leaves. This device allows researchers to perform real-time and non-destructive measurements of these important plant metabolites, which are crucial indicators of plant health and stress responses. Developed by Force-A, the sensor is a result of technology transfer from the CNRS and University of Paris-Sud Orsay. It allows to make instant measurements without damaging the leaves. The main applications are plant sciences and agricultural research.