Extraction of basil seed mucilage using ionic liquid and preparation of AuNps/mucilage nanocomposite for catalytic degradation of dye.

Basil seeds are widely cultivated throughout the world because of their extensive applications in various fields of life. The Basil seeds mucilage (BSM) exhibits remarkable physical and chemical properties like high water absorbing capacity, emulsifying, and stabilizing properties. The extraction of this mucilage from the seed surface has always been done by physical and chemical methods, which has certain drawbacks. Here, we report for the first time a chemical method for the effective extraction of this mucilage using ionic liquids (ILs); the green solvents. Pyridinium chloride based ILs were investigated for the effective extraction of mucilage and the process was optimized for various variables i.e. time, temperature, basil seed loading, co-solvents, anti-solvents. The extraction yield (up to 25% w/w of mucilage per basil seeds dry weight) was obtained at optimum conditions. Extracted mucilage was characterized by analytical techniques. The extracted BSM was used to prepare AuNps/BSM nanocomposite by stabilizing the gold nanoparticles. The AuNps/BSM nanocomposite was applied for the catalytic degradation of dyes (congo red; 12 min, methyl orange; 4 min, whereas 4-nitrophenol; 6 min).