Characterizing the localized surface plasmon resonance behaviors of Au nanorings and tracking their diffusion in bio-tissue with optical coherence tomography

Abstract

The characterization results of the localized surface plasmon resonance (LSPR) of Au nanorings (NRs) with optical coherence tomography (OCT) are first demonstrated. Then, the diffusion behaviors of Au NRs in mouse liver samples tracked with OCT are shown. For such research, aqueous solutions of Au NRs with two different localized surface plasmon resonance (LSPR) wavelengths are prepared and characterized. Their LSPR-induced extinction cross sections at 1310 nm are estimated with OCT scanning of solution droplets on coverslip to show reasonably consistent results with the data at individual LSPR wavelengths and at 1310 nm obtained from transmission measurements of Au NR solutions and numerical simulations. The resonant and non-resonant Au NRs are delivered into mouse liver samples for tracking Au NR diffusion in the samples through continuous OCT scanning for one hour. With resonant Au NRs, the average A-mode scan profiles of OCT scanning at different delay times clearly demonstrate the extension of strong backscattering depth with time. The calculation of speckle variance among successive OCT scanning images, which is related to the local transport speed of Au NRs, leads to the illustrations of downward propagation and spreading of major Au NR motion spot with time.

Review of speckle and phase variance optical coherence tomography to visualize microvascular networks

“…89 With resonant Au nanorings (Au-NRs), the distributions of nanorings were deeper inside the sample with time. However, with a high concentration of the Au-NRs solution, the overall localized surface plasmon resonance (LSPR) behavior became weaker than that of individual Au-NRs.…”

Investigation of temporal vascular effects induced by focused ultrasound treatment with speckle-variance optical coherence tomography

“…N is the total number of B-scan frames used for speckle-variance estimation. Normally, the occurrence of speckle variance results from moving particles in biological tissue, such as blood flow [36,[38][39][40] or nanoparticle diffusion [37]. Since no extraneous particles were used in our experiment, the speckle variance was due to contributions from red blood cell (RBC) extravasations.…”

Highly sensitive biochemical sensor comprising rectangular nanometal arrays

“…Thus, LSPR sensors have been adopted in numerous fields including chemistry, biochemical sensing, label-free detection, and optoelectronics [22][23][24][25][26][27][28][29][30][31].…”