Binding quantum dots to amino-functionalized graphene surfaces using amidation reaction Jörg Rappich 1, T. J. Neubert 1 , K. Hinrichs 2 and N. H. Nickel 3 1 Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Germany 2 Leibniz-Institut für Analytische Wissenschaften – ISAS – e. V., Application Labs Berlin, Schwarzschildstr. Berlin, Germany 3 Department Nanoscale Solid-Liquid Interfaces, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Schwarzschildstr, Berlin, Germany Chemical vapour deposition was used to grow large-area graphene on Cu-foil. In a following step the graphene was functionalized by p ‑aminophenyl groups via the electrochemical diazonium-route. Subsequently, carbonic acid modified CdS X Se 1-X /ZnS quantum dots (QDs) were immobilized via amidation reaction to the functionalized graphene forming stable bonds to the amino groups. Finally, the QD-modified graphene was transferred to a SiO 2 covered Si wafer without losing the QD-modification. The successful binding of the QDs onto the p ‑aminophenyl functionalized graphene was investigated by their vibrational signature using infrared-spectroscopic ellipsometry, Raman backscattering, and their specific light emission as measured by photoluminescence spectroscopy. The QDs had a maximum emission wavelength of 540 nm and 630 nm, respectively. The QDs served as model systems with a diameter of 6 nm which is similar to the size of protein complexes like haemoglobin (5.5 nm). This example also shows a possible way for binding of bigger biomolecules (e.g. DNA or RNA) on such p ‑aminophenyl functionalized surfaces. References 1. X. Zhang, G. Sun, K. Hinrichs, S. Janietz, J. Rappich, Infrared spectroscopic study of the amidation reaction of aminophenyl modified Au surfaces and p-nitrobenzoic acid as model system., Phys. Chem. Chem. Phys. 12 (2010) 12427–12429. 2. F. Rösicke, M. A. Gluba, K. Hinrichs, G. Sun, N. H. Nickel, J. Rappich, Quantifying the electrochemical maleimidation of large area graphene, Electrochem. commun. 57 (2015) 52-55.
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