New Scientific Publications in 2021 featuring O-PTIR and IR + Raman
So far this year there have already been three scientific publications featuring the breakthough techniques of O-PTIR and IR + Raman. Here’s an overview of the papers, with links to where you can download them.
What is O-PTIR?
Optical Photothermal Infrared spectroscopy is a fast and easy to use non-contact optical technique, which overcomes the IR diffraction limit.
- Sub-micron spatial resolution.
- Non-contact technique.
- Spectra are comparable to FTIR, without the dispersive artifacts of ATR.
- Samples do not need to be thin, so there’s little or no sample preparation.
Simultaneous IR and Raman
Sub-micron infrared can be combined with Raman for simultaneous IR and Raman on the same spot, with the same resolution. This is a world first, opening up a whole new range of research possibilities. More about IR and Raman…
Analysis of Fixed and Live Single Cells Using Optical Photothermal Infrared with Concomitant Raman Spectroscopy
By Alice Spadea, Joanna Denbigh, M. Jayne Lawrence, Mustafa Kansiz, and Peter Gardner
This paper describes the first use of O-PTIR for obtaining infrared spectra of both fixed and living cells using a quantum cascade laser and optical parametric oscillator laser as excitation sources. This enables all biologically relevant vibrations to be analysed at sub-micron spatial resolution.
Infrared data acquisition is also combined with concomitant Raman spectra from the same location, for a full vibrational profile of the cell.
Pancreatic and breast cancer cell lines are used to demonstrate the capabilities of the new instrumentation. The modalities are combined to analyse sub-cellular structures in both fixed and, more importantly, live cells under aqueous conditions. Protein secondary structure and lipid-rich bodies are identified on the sub-micron scale.
Read the publication
The paper was published in Analytical Chemistry in February 2021. Read it online or download a pdf on ACS Publications:
Life Science with O-PTIR: Online Workshop
Wednesday 14th April 2021, 1pm BST / 2pm CEST
Alice Spadea will discuss this research at our online workshop, with opportunities to ask questions in a live Q&A. Details and registration…
Imaging Isotopically Labeled Bacteria at Single-Cell Level Using High-Resolution O-PTIR
By Cassio Lima, Howbeer Muhamadali, Yun Xu, Mustafa Kansiz and Royston Goodacre
This paper investigates the cellular uptake of stable isotope-labeled compounds by bacteria at the single-cell level using infrared spectroscopy. This monitors the chemical vibrations affected by the incorporation of “heavy” atoms by cells and can therefore be used to understand microbial systems.
This is a significant advancement because the majority of previous research focused on evaluating communities of cells, due to the limited spatial resolution of standard IR microspectrometers. No other study has evaluated the incorporation of labeled compounds by bacteria at single-cell levels using infrared.
The ability to study the metabolic activity of a single bacterium is significant, contributing a better understanding of the interactions between microorganisms, as well as the function of individual members and their interactions in microbial communities.
This paper demonstrates the capabilities of O-PTIR for monitoring the uptake of 13C-glucose and 15N-ammonium chloride by Escherichia coli bacteria at single-cell levels using spectral signatures recorded via single-point and imaging modes.
Imaging was achieved using six vibrational bands in the amide I and II regions, which were analysed with chemometrics by employing partial least squares-discriminant analysis to predict 13C/12C and 15N/14N simultaneously.
Read the publication
The paper was published in Analytical Chemistry in February 2021. Read it online or download a pdf on ACS Publications (log-in or purchase required):
Delighted that our @LivUniCMR @LivUniISMIB paper on imaging isotopically labeled bacteria at single-cell level using optical photothermal infrared #mIRage with @theonlycassio @Howbeer @yunxumanchester @mkansiz5 is now out in @an_chem. Hope you enjoy it:https://t.co/Eim2giAMbP pic.twitter.com/Z7vNpVcf4a— Roy Goodacre (@RoyGoodacre) February 17, 2021
Resolving Nanocomposite Interfaces via Simultaneous Sub-micrometer Optical‐Photothermal Infrared‐Raman Microspectroscopy
By Alexander J. Wang, Eoghan P. Dillon, Surendra Maharjan, Kang‐Shyang Liao, Brian P. McElhenny, Tian Tong, Shuo Chen, Jiming Bao and Seamus A. Curran
Developing new multi-phase nanostructures and nanoscale systems involves characterising and visualising nanoscale interphases/interfaces. The issue with standard IR techniques is that their spatial resolution is limited by the wavelength‐dependent diffraction limit of IR light (≈5–12 µm).
Optical‐photothermal infrared (O‐PTIR) with simultaneous hyper-spectral Raman microspectroscopy is a new all‐optical technique that overcomes these diffraction limits. It delivers position‐specific IR spectra with sub‐micrometer wavelength‐independent resolution across the mid‐IR.
The research presented in this publication uses single‐frequency O‐PTIR with concomitant hyper-spectral Raman micro-spectroscopy to resolve interfacial regions in a poly(octadecyl acrylate)‐grafted‐multiwall carbon nanotube (PODA‐g‐MWCNT) nanocomposite for wearable temperature sensors. It highlights how O‐PTIR + Raman can be used for analytical characterisation and visualisation of nanocomposite systems below the resolution limits of conventional IR spectroscopy.
Read the publication
The paper was published in Advanced Materials Interfaces in January 2021. Read it online or download a pdf on Wiley Online Library (log-in or purchase required):
Blue Scientific is the official distributor of O-PTIR systems from Photothermal Spectroscopy Corp in the UK and Nordic region. We’re available to provide quotes and answer all your questions – just get in touch: