Rod-likegoldnanoparticlescanbeformedfromHAuCl4aqueoussolutionwithultraviolet(UV)irradiationintheabsenceoftemplates,avoidingpossiblepoisonoussurfactantembeddedintothesurfaceoffunctionalgoldnanoparticlesappliedinbiomedicine.Theaspectratioofnanorodsrangesfrom1.1to4.4withtheconcentrationofHAuCl40.2mM,whichcanbeverifiedbyHRTEMimagesandtheabsorptionspectrum.Itisfoundthatthenanoclusterwithseveralatomsoccurspriortotheformationofnanorods,highlycorrespondingtoitstypicalabsorptionspectrum.TracingtheevolutioninabsorptionspectraofHAuCl4aqueoussolution,itcanbeconcludedthattheformationmechanismofgoldnanoparticlesinthisprocessisdifferentfromthatintheconventionalinductivegrowthmodel,possiblyinagrowthpatternwithimperfectorientedattachment(IOA)relevanttothecolliding-and-growing.
