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Photothermal optical coherence tomography for investigation and imaging photothermal trapping of gold nano-rods in clear media and biological tissue

Hu, Yong, Podoleanu, Adrian G.H., Dobre, George (2019) Photothermal optical coherence tomography for investigation and imaging photothermal trapping of gold nano-rods in clear media and biological tissue. Journal of Optics, 21 (9). Article Number 95301. ISSN 2040-8978. (doi:10.1088/2040-8986/ab295d) (KAR id:74407)

Abstract

A quantitative spectrometer-based photothermal optical coherence tomography (PT-OCT) system is employed to investigate and image the photothermal trapping of gold nano-rods (GNRs) in clear and biological media. The PT-OCT system is calibrated through dynamic phase measurements of piezo motion with known driving parameters. We measure and compare the displacement sensitivities of the PT-OCT system at different camera exposure time settings in two configurations: with a distinct reference path; and with a common path. The displacement sensitivity of the system in the common path configuration is improved from 1.5 nm to 0.17 nm by performing Fourier analysis on the output phase. The minimum Ti:Sa power capable of inducing a detectable photothermal response of GNRs is measured to be 0.5 mW. This value agrees with the latest reported minimum Ti:Sa power for photothermal trapping GNRs. The PT-OCT system is used to generate en-face images of photothermal trapped GNRs in the water solution and in the biological tissue. By displaying the difference between successive en-face phase images, spatial distribution patterns of the aggregated GNRs, resulted from the photothermal trapping, are clearly outlined with great contrast. The photothermal trapping of GNRs in tissue shows a greater complexity than in the clear media. The limitation of the PT-OCT technology is discussed. The study proves the potential of PT-OCT for imaging the photothermal trapping of GNRs.

Item Type: Article
DOI/Identification number: 10.1088/2040-8986/ab295d
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: George Dobre
Date Deposited: 14 Jun 2019 15:29 UTC
Last Modified: 11 Jan 2024 10:01 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/74407 (The current URI for this page, for reference purposes)

University of Kent Author Information

Hu, Yong.

Creator's ORCID:
CReDIT Contributor Roles:

Podoleanu, Adrian G.H..

Creator's ORCID: https://orcid.org/0000-0002-4899-9656
CReDIT Contributor Roles:

Dobre, George.

Creator's ORCID: https://orcid.org/0000-0002-5695-2591
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