A novel approach for optical biosensing can be obtained based multiphoton induced luminescence (MIL) and its dependence on plasmonic coupling. It has been shown that the proximity of spherical AuNPs determines the generation of MIL in far-field multiphoton laser scanning microscopy (MPM). A stimuli responsive contrast mediator with high sensitivity can be created by controlling the aggregated state of AuNP. In this study we explore a system based on spherical AuNPs functionalized with β-cyclodextrin and multiple β-D-lactose units (lacto-CD-AuNP). The aim of the β- D-lactose units is to target cancer cells, based on overexpression of galectin3 (Gal-3) receptors. The results demonstrate that clustering of particles, and thereby MIL signal, was only acquired from tumor cell lines, i.e., SK-MEL-28 and A431, while not from normal keratinocytes (HEKn). Thus further studies should be undertaken to translate the concept to a preclinical setting.
Heterodimerization between designed helix-loop-helix polypeptides was utilized in order to assemble gold nanoparticles
on planar substrates. The peptides were designed to fold into four-helix bundles upon dimerization. A Cys-residue in the
loop region was used to immobilize one of the complementary peptides on a maleimide containing SAM on planar gold
substrates whereas the second peptide was immobilized directly on gold nanoparticles. Introducing the peptide
decorated particles over a peptide functionalized surface resulted in particle assembly. Further, citrate stabilized
particles were assembled on amino-silane modified glass and silicon substrates. By subsequently introducing peptides
and gold nanoparticles, particle-peptide hybrid multi layers could be formed.