Plasmonic chiral contrast agents for optical coherence tomography: numerical study

Abstract

Optical coherence tomography (OCT) is a widely used morphological imaging modality. Various contrast agents, which change localized optical properties, are used to extend the applicability of OCT, where intrinsic contrast is not sufficient. In this paper we propose the use of a dual-rod gold nano-structure as a polarization sensitive contrast agent. Using numerical simulation, we demonstrated that the proposed structure has tunable chiral response. Enhanced cross-section due to Plasmon resonance in gold nanoparticles, along with the chiral behavior can provide enhanced detection sensitivity. The proposed contrast agents may extend the applicability of OCT to the problems that require the molecular contrast with enhanced sensitivity.

Combined lineage mapping and gene expression profiling of embryonic brain patterning using ultrashort pulse microscopy and image registration

“…65,66 These tissues are turbid compared with the 24 hpf embryo, and we could only find one report of OCM imaging on 24 hpf zebrafish 67 in which the signal seemed comparable with our data, relatively weak, presumably due to the transparency of the embryo. There have been efforts to use OCM for imaging with molecular contrast such as detecting backscattered light from gold nanoparticles conjugate to antibodies for immunodetection 68,69 and using spectral domain detection to look for absorption signatures of specific molecules such as hemoglobin. There have been efforts to use OCM for imaging with molecular contrast such as detecting backscattered light from gold nanoparticles conjugate to antibodies for immunodetection 68,69 and using spectral domain detection to look for absorption signatures of specific molecules such as hemoglobin.…”

Magnetic and Plasmonic Contrast Agents in Optical Coherence Tomography

“…The authors were able to contrast diffusion of these nanorings against native tissue by mapping OCT speckle variance within the image to track the diffusion of these particles over time [126]. Exploiting the optical anisotropy of nanorods, Mehta and Chen used simulations to show enhanced polarization sensitive contrast using a chiral nanostructure constructed from two nanorods [127]. Chhetri et al used this polarization sensitivity to monitor rotational motion of rods, whose movement about the axis results in polarization dependent intensity fluctuations.…”

Dark-field circular depolarization optical coherence microscopy

“…To overcome the poor contrast associated with conventional contrast mode of OCM, various groups have developed contrast mechanisms with differentiable property compared to background tissue [11][12][13][14][15]. These differentiable behaviors allow effective suppression of background, leading to enhanced contrast and sensitivity.…”

“…Differentiable polarization response is one of the effective mechanisms for contrast enhancement. Recently, we proposed chirality based polarization differential response to effectively suppress background signal to improve sensitivity of gold nanostructures [14].…”