Figure 4
Immobilization of AuNPs on patterned ATPES/PEG-silane bi-composite self-assembled monolayers (SAMs) on a glass slide. (a) Schematic illustration of bi-composite patterning via μCP and DFGP. 1st APTES ink was firstly patterned by μCP, then 2nd PEG-silane ink was injected by DFGP. After washing the patterned surface, AuNPs covered the entire patterned surface for 30 s and then were washed. (b) optical image of a PDMS stamp for AuNP patterning (top) and schematic diagram of APTES and PEG-silane patterned glass (bottom). (c) A dark-field image of AuNP patterning with circular dot patterns. Inserted images represent scattering color with a dark-field microcope. Inset indicates an enlarged dark-field image to display the scattering color. (d) Representative scattering spectra. A single bare AuNP (black line, position 1) and aggregated AuNPs due to plasmon coupling via neighbouring AuNPs (red line, position 2) (e) Line profiles (f) A dark-field image of AuNPs on a reverse bi-composite SAM surface (PEG-silane/APTES). The scale bars represent 50 μm.
