Networks of gold nanoparticles and bacteriophage as biological sensors and cell-targeting agents

doi:10.1073/pnas.0509739103

Networks of gold nanoparticles and bacteriophage as biological sensors and cell-targeting agents

^*University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030;^†Burnham Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037;^¶Department of Chemistry, George Washington University, 725 21st Street NW, Washington, DC 20052; and^‡Harvard Medical School and Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Institutes of Medicine, 77 Avenue Louis Pasteur, Boston, MA 02115

Contributed by Richard L. Sidman, November 10, 2005

Abstract

Biological molecular assemblies are excellent models for the development of nanoengineered systems with desirable biomedical properties. Here we report an approach for fabrication of spontaneous, biologically active molecular networks consisting of bacteriophage (phage) directly assembled with gold (Au) nanoparticles (termed Au–phage). We show that when the phage are engineered so that each phage particle displays a peptide, such networks preserve the cell surface receptor binding and internalization attributes of the displayed peptide. The spontaneous organization of these targeted networks can be manipulated further by incorporation of imidazole (Au–phage–imid), which induces changes in fractal structure and near-infrared optical properties. The networks can be used as labels for enhanced fluorescence and dark-field microscopy, surface-enhanced Raman scattering detection, and near-infrared photon-to-heat conversion. Together, the physical and biological features within these targeted networks offer convenient multifunctional integration within a single entity with potential for nanotechnology-based biomedical applications.

Footnotes

↵ § To whom correspondence may be addressed. E-mail: richard_sidman{at}hms.harvard.edu, rpasqual{at}mdanderson.org, or warap{at}mdanderson.org.
Author contributions: G.R.S., D.R.C., F.I.S., M.G.O., R.L.S., J.H.M., W.A., and R.P. designed research; G.R.S., D.R.C., F.I.S., and M.G.O. performed research; E.Y.S., R.L.S., J.H.M., W.A., and R.P. contributed new reagents/analytic tools; G.R.S., D.R.C., F.I.S., M.G.O., J.H.M., W.A., and R.P. analyzed data; and G.R.S., D.R.C., F.I.S., M.G.O., R.L.S., J.H.M., W.A., and R.P. wrote the paper.
Conflict of interest statement: No conflicts declared.
Abbreviations: imid, imidazole; NIR, near infrared; SERS, surface-enhanced Raman scattering; TEM, transmission electron microscopy; TU, transducing units; Df, fractal dimension.
Freely available online through the PNAS open access option.