A Polydiacetylenes-Based Sensor for Discriminating Oleic Acid from Stearic Acid and Elaidic Acid

We have explored the application of IM-PDAs as chemosensor system for the detection of oleic acid in aqueous solution. Among the various fatty acids, IM-PDAs displayed a selective colorimetric change from blue to red, as well as fluorescence enhancement. Most importantly, the presence of oleic acid can be easily monitored via naked-eye detection. Oleic acid, a monounsaturated fatty acid, is the most abundant fatty acid in human adipose tissue. As positive health effects, oleic acid may hinder the progression of adrenoleukodystrophy (ALD), which is a fatal disease that affects the brain and adrenal glands and attacks the myelin sheaths of the body, causing symptoms similar to those in multiple sclerosis. Numerous studies indicate that a diet containing rich oleic acid can lower serum cholesterol by diminishing oxidative stress and inflammatory mediators while promoting antioxidant defenses. In addition to being used as an excipient, oleic acid is often used widely as an emulsifying or solubilizing agent in pharmaceuticals and cosmetics. On the other hand, the deleterious effects of oleic acid have been attributed to increases in the permeability of both vascular and alveolar epithelium to solute, caused by changes in membrane fluidity and increases in intracellular calcium concentration