Development of functionalised nanoparticles for cancer imaging using surface enhanced spatially offset resonance Raman spectroscopy

Lead Research Organisation: University of Strathclyde
Department Name: Pure and Applied Chemistry

Abstract

Spatially offset Raman spectroscopy (SORS) is a method used for accurate and robust chemical analysis of objects where the contents are obscured by an opaque layer or container for example for screening the contents of containers at airports for explosives. It involves interrogating a sample with an incident laser beam and measuring the scattered light at a distance offset from the illumination area, this allows Raman responses to be obtained from at depth within a sample. Further advances in deep Raman techniques have led to the combination of both surface enhanced Raman scattering (SERS) and SORS together, referred to as SESORS. This opens the way for detecting a number of analytes at even greater depths due to the enhanced Raman response achievable. Our recent paper introducing the concept of SESORS, reached a key milestone in deep Raman spectroscopy by demonstrating the possibility of probing signals from SERS nanoparticles buried, or injected into tissues from depths significantly deeper (25 mm) than that previously achieved in epi-Raman approaches. Our initial collaboration with Dstl using a hand help SORS device was also recently published.
This project, in collaboration with Dstl will use a portable SORS system supplied by Dstl, to assess the ability to detect SERS nanotags behind a range of barriers, such as thick plastics (1-5 mm thick), coloured glass and cardboard. This will involve developing suitably labelled SERS active nanotags which give a strong SERS response at 785 nm and above. This will require synthesising different types of metal nanoparticles which have absorbances towards the infrared region of the electromagnetic nanoparticles and developing coatings for the nanoparticles which are stable in the environment in which they will act as a label. This will involve exploring the encapsulation of labelled nanoparticles in for example different polymers or silica. These will then be used inside different barrier materials, of varying, known, thickness, and used to optimise the SORS/SESORS system for each material.
Once the system has been optimised to give maximum SERS response at depth, the system will also be used for the detection of nanotags inside biological material. For example, the detection of nanotags inside tissue to simulate the detection of target nanotags in vivo.
Objectives
(1) To explore the synthesis of metal nanotags with red shifted absorbances. This will involve synthesising nanoparticles with different sizes, shapes and shell structures.
(2) Evaluate matrices which can be used to protect or encapsulate the labelled nanoparticles and protect them from the environment and investigate their use with 785 nm laser excitation and above.
(3) Raman detection of analytes and SERS active nanotags using SORS in various containers made of for example plastic, glass, paper etc. The thickness of the containers will also be varied.
(4) SORS detection of nanotags at depth within biological material e.g. tissue samples.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/R513349/1 01/10/2018 30/09/2023
2188558 Studentship EP/R513349/1 01/03/2019 31/08/2022 Melissa Benison