Synthesis of shape-anisotropic nanoparticles and their application
in: Temporal Proceedings (2018)
Localized Surface Plasmon Resonance (LSPR) is a characteristic effect visible for different metal nanoparticles, like gold, silver, platinum or palladium particles. This effect is based on the excitation of free electrons in the metal by light of sufficient wavelength corresponding to the resonance frequency which is depending on the refractive index, size and shape of the nanoparticles.1 The light energy introduced to the particle can then decay by scattering, electron-hole-pair formation or conversion to thermal energy, which offers a broad field of application for such particles like spectroscopy, sensing or catalysis.2 Here, especially form anisotropic nanoparticles are of great interest, like nanorods, prisms or cubes as anisotropic nanoparticles exhibit a very large energetic field due to their tips and edges, creating centers of high energy.3 Classical wet-chemical synthesis of such anisotropic nanoparticles is nowadays state of the art, however it is still challenging to obtain uniform particles with a narrow size distribution, which is required for most applications. A technique very helpful to fulfill this goal is microfluidics, as it guarantees a strictly defined addition of educts and their regular mixing within the microfluidic reactor by a low-consumption of chemicals. Like this, our group was able to transfer the synthesis of shape-anisotropic gold nanocubes from the batch to microfluidics with promising results regarding manageability of reaction process and resulting particle size and distribution.4,5 Furthermore a novel method was established to remove the blocking agent cetyltrimethylammonium chloride (CTAC) from the surface of Au nanocubes, which is necessary for cube synthesis but hindering for most applications. This allows us to make also such particles available for applications like biosensing or plasmon catalysis.6
1. A. Csáki, M. Thiele, J. Jatschka, A. Dathe, D. Zopf, O. Stranik and W. Fritzsche,
Engineering in Life Sciences, 2015, 15, 266-275.
2. S. Linic, P. Christopher and D. B. Ingram, Nature Materials, 2010, 10, 911 – 921.
3. S. Sarina, E. R. Waclawik and H. Zhu, Green Chemistry, 2013, 15, 1814 – 1833.
4. M. Thiele, J.Z.E. Soh, A. Knauer, D. Mallsch, O. Stranik, R. Müller, A. Csáki, T.
Henkel, J. M. Köhler and W. Fritzsche, Chemical Engineering Journal, 2016, 288,
432 – 440.
5. M. Thiele, A. Knauer, D. Mallsch, A. Csáki, T. Henkel, J.M. Köhler and W.
Fritzsche, Lab on a Chip, 2017, 17, 1487 – 1495.
6. C. Singh, M. Thiele, A. Dathe, O. Stranik, T. Henkel, G. Sumana, W. Fritzsche
und Andrea Csáki, manuspcript to be submitted.