Tweaking homogeneity and stability of gold nanorods by synergistic action of pH and temperature

Commonly used seed-mediated method of gold nanorod synthesis has limitations like formation of by-products (stars, squares, dog-bones, platelets), slow but continuous growth during storage/ageing which adversely affects their homogeneity. Storage in the presence of cetyltrimethylammonium bromide (CTAB) is also essential to prevent their aggregation, which being toxic, needs to be removed before using them for biological applications. We herein, present a simple approach to overcome these limitations through synergistic action of low pH and high temperature. The proposed modifications synthesize highly homogeneous nanorods which are stable upto months even when stored in water. Copyright © 2018 VBRI Press.