Gold nanoparticles: an era in bionanotechnology.

INTRODUCTION: Gold nanoparticles have been efficiently and effectively used for the delivery of biomolecules and genes along with the potential to offer extremely sensitive diagnostics and imaging methods. AREAS COVERED: This review discusses the historical aspects, synthesis of gold nanoparticles, gold nanoparticles as drug delivery vehicles, photothermal effect of gold nanoparticles and the applications of gold nanoparticles. Gold nanoparticles with their unique optical properties may be useful as biosensors in living cells and has application in the field of drug delivery and photothermal therapy. Depending on the size, shape and degree of aggregation and nature of the protecting organic shells on their surface, gold nanoparticles can appear red, blue and other colors and emit bright resonance light of various wavelengths, which falls under visible region. Because of this property, gold nanoparticles have been extensively used as probes for sensing/imaging a wide range of analysts/targets such as proteins, cells and nucleic acids. EXPERT OPINION: Gold nanoparticles provide an admirable platform for the delivery of biomolecules and genes.