Synthesis and modelling of gold nanostars with tunable morphology and extinction spectrum

We present a simple seed-less synthesis procedure to fabricate stable gold nanostars (AuNSs) with tunable extinction properties from the visible up to 1800 nm, depending on the average values of core size and branch length. The experimental results are compared with data from Finite Elements Method computations by using an approximated model of the fabricated branched systems. The theoretical computations highlight the existence of hot spots located on the tips of the nanostars even up to 1800 nm wavelength, which opens the way to the improvement of IR diagnostics or chemical sensing.