Noble metal nanocrystals are very promising for sensing applications, because their plasmon resonances are highly dependent on the surrounding environment. However, their practical applications are hindered by the poor stability of the colloidal solutions and the high cost of single-particle spectroscopy. We have developed a new method for directly depositing colloidal metal nanocrystals from solutions onto different substrates. The resultant nanocrystal arrays are uniform and dense, with the single-layer absorbance value reaching 0.4 and the size up to one decimeter square. We characterized the refractive index sensitivities of Au nanorod arrays with and without capping molecules (CTAB, PEG) deposited on glass slides, mesoporous silica and titania films. The nanorods on the titania film exhibit the highest index sensitivity. Furthermore, the nanocrystal arrays can be transferred to various substrates (silicon, graphene, plastics). Our method is expected to greatly facilitate the plasmonic applications that require the formation of large-area metal nanocrystal arrays.

Macro-scale colloidal noble metal nanocrystal arrays for refractive index-based sensing applications

245th National Meeting (2013)

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