Skip to main content
. Author manuscript; available in PMC: 2012 Sep 24.
Published in final edited form as: ACS Nano. 2011 Jun 13;5(7):5383–5389. doi: 10.1021/nn2002807

Figure 1.

Figure 1

a) Core-satellite Au nanoassemblies before and after proteolytic cleavage. b) Immobilization of the negatively charged AuNP cores is enabled by Coulombic electrostatic attraction to an APTES monolayer on glass. The glass slide is subsequently passivated with an mPEG chain to block nonspecific satellite adsorption. c) Satellite attachment is enabled by a directional cysteine/biotin-streptavidin peptide tether. d) The addition of trypsin cleaves the peptide, releasing the satellites into solution and enabling colorimetric detection of the protease.