A novel methodology for the preferential end functionalization of Au nanorods with nanoparticles is reported by exploiting the electrostatic attractive interactions. The enhanced potential at the edges of Au nanorods preferentially attracts the positively charged Au nanoparticles, leading to their selective binding. Site-specific binding results in a spontaneous bathochromic shift in the longitudinal plasmon band of Au nanorods which is dependent on the size of the nanoparticles.