Branched metal nanoparticles: a review on wet-chemical syntheses and biomedical applications

Abstract

Branched metal nanoparticles present a promising new class of materials, which have great potential as sensors, catalysts, drug carriers, and imaging agents, owing to their unique nanostructures, physicochemical properties, optical properties, and other characteristics. Many efforts have recently been devoted to the wet-chemical synthesis of branched metal nanoparticles. Seed-mediated growth and seedless growth are two main routes for producing branched metal nanoparticles. Most particle synthesis methods can be modified for different metal systems. In this review, various synthesis methods for the fabrication of branched monometallic, bimetallic, and multimetallic nanoparticles and also branched polymer core-metal nanoshell composite nanoparticles are summarized, catagorized, and discussed. The relevance and performance of such nanostructured materials with regard to their optical properties which arise from localized surface plasmon resonances are summarized, and their potential as excellent substrates for surface enhanced Raman scattering (SERS) is reviewed. Other applications of branched nanoparticles such as drug delivery vehicle, medical imaging agent, catalysis, and magnetism are briefly introduced.