Biomolecule-tailored assembly and morphology of gold nanoparticles for LSPR applications

Gold nanoparticles (GNPs) have attracted the particular attention of nanoscience and nanoengineering due to their unique localized surface plasmonic resonance (LSPR) derived optical, electronic and magnetic properties. These LSPR-based properties are highly dependent on the nanostructures of GNPs which could be precisely tuned via strategies of assembly and morphological regulation. Biomolecules (DNA, amino acids and peptides) serving as linking and capping agents are capable to program the assembling and tailor the morphological evolution of GNPs to achieve varying nanostructures and plasmonic properties as well as biofunctionalities due to their specific recognition capabilities and unique interface affinity with GNPs. Versatile applications based on tunable LSPR properties of plasmonic nanoprobes composed of GNPs and biomolecules, therefore, have been successfully demonstrated in various fields, including metal-enhanced fluorescence, dark-field microscopy imaging, colorimetric assay, plasmonic circular dichroism-based assay, surface-enhanced Raman scattering-based bioprobes and LSPR shift-based biosensing, etc. This review introduces the recent advances in the design, structural tuning, property characterization and biosensing and bioimaging applications of these plasmonic nanoprobes, with detailed examples in previous applications and prospective discussions for their developments in future.