Smartphone-enabled Green Anthocyanin Sensor for Fe(III) Sensing on Paper Using Capillary-Driven Microfluidics

•Anthocyanin-based smartphone-enabled sensor for on-site Fe(III) detection in water.•Ultra-cost-effective, user-friendly, and environmentally sustainable sensor.•Detection within seconds with minimized interference through the use of a stable buffer on detection zone.•Sustainability assessment by applying the principles of the analytical GREEnness (AGREE) test.