Long-range two-photon scattering spectroscopy ruler for screening prostate cancer cells

Abstract

Development of a long-range TPS ruler for the screening of prostate cancer cells with sensitivity of 5 cells per mL level is demonstrated.

Multimodal Nonlinear Optical Imaging of Live Cells Using Plasmon-Coupled DNA-Mediated Gold Nanoprism Assembly

“…The strong one is the in-plane dipole band with λ max ≈ 1300. The weaker one at λ max ≈ 800 nm is quadrupole band, as reported before 34–39 .…”

“…Triangular gold nanoprisms (60 ± 10 nm edge length, 5.5 ± 0.5 nm thick) were synthesized using seeded mediated growth method, as we and others have reported before 34–39 . In the first step, gold seeds were prepared by the reduction of HAuCl 4 in the presence of sodium thiosulfate (Na 2 S 2 O 3 ) as reducing agent.…”

“…After two days of incubation the cell viability was determined using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and typan blue assay, as we have reported before 10,13,39 .…”

“…Triangular-like gold nanoprisms possess strong electric field enhancement on the tip and exhibit high photo-stability and biocompatibility and as result, they are very good candidates for bio-imaging using a two-photon microscope 3,11,34–39 . In nano-assembly, due to the presence of strong multipolar mode (l >1) band with dipolar mode ( l=0), one can utilize both models to enhance optical properties 10,15–20 .…”

“…For gold nanoprism, when light interacts in the surface, it couples with free-electron excitations near the surface and produces surface plasmon polaritons 3,11,34–39 . Due to the strong electromagnetic fields developed by the light confinement on the surface and lightning rod effect at the corner 3,11,34–39 , weak two photon process can be significantly increased by 4–6 orders of magnitude. For further huge enhancement of two photon nonlinear processes, we have developed plasmon-coupled DNA mediated nano-assembly where plasmonic nanostructures are in close proximity.…”