Biosynthesis of anisotropic gold nanoparticles using Maduca longifolia extract and their potential in infrared absorption

Metal nanoparticles, in general, and gold nanoparticles, in particular, are very attractive because of their size- and shape-dependent properties. Biosynthesis of anisotropic gold nanoparticles using aqueous extract of Madhuca longifolia and their potential as IR blockers has been demonstrated. The tyrosine residue was identified as the active functional group for gold ion reduction. These gold nanoparticles were characterized by of UV–Vis spectrophotometer, FTIR, TEM and HrTEM. The presence of proteins was identified by FTIR, SDS-PAGE, UV–Vis and fluorescence spectroscopy. The micrograph revealed the formation of anisotropic gold nanoaprticles. The biologically synthesized gold nanotriangles can be easily coated in the glass windows which are highly efficient in absorbing IR radiations.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Anisotropic gold nanoparticles were synthesized using Maduca longifolia leaf extract for the first time. ► We identified the plant proteins are found to be active biomolecules involved in synthesis of gold nanoparticles. ► The hydroxyl group in tyrosine residue was found to be responsible for reduction of noble metal ions. ► The NIR absorption of gold nanotriangles has important application as IR blocker in optical coating in building windows.