Low-Cost Epoxy-Cast Serpentine Lab-on-Chip with Pre-loaded Methyl Red for Smartphone-Based Colorimetric Screening of Free Acidity in Edible Oils. CI [Internet]. 2026 Oct. 12 [cited 2026 Oct. 12];3(3):34-41. Available from: https://cheminters.com/index.php/jci/article/view/102