Programmed self-assembly of nanoparticles directed by enzyme has been widely used in bioanalysis. Herein, we report a unique and simple colorimetric biosensor for efficient enzyme detection based on bidirectional self-assembly/disassembly of gold nanoparticles (GNPs). We exploited a �trimethyl lock�-peptide conjugated substrate with esterase and protease active sites. Upon the treatment of esterase, the conjugated substrate released central peptide linker which contains thiol- and amino-terminus induced GNPs self-assembly followed by the distinct color change from red to blue. Then, the aggregated GNPs further interacted with protease which selectively cleaved peptide sequence and subsequently driven GNPs disassembly. Therefore, the bidirectional self-assembly of GNPs was achieved by enzyme actuations with the significant color change from red to blue and back to red again. Based on this bidirectional assay, enzyme activities could be efficiently evaluated by color change, UV-vis spectra shifts and surface enhanced Raman scattering (SERS). This enzyme-switching of GNPs networks could be useful in wide areas of nanobiotechnology and will have profound applications in medical therapy and diagnostics.

Manipulating self-assembly/disassembly of gold nanoparticles by enzyme activities

239th National Meeting (2010)

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