Detection of glycine as a model protein in blood serum using 2D-IR spectroscopy

Samantha H. Rutherford, Gregory M. Greetham, Paul M. Donaldson, Michael Towrie, Anthony W. Parker, Matthew J. Baker, Neil T. Hunt

Research output: Contribution to journalArticlepeer-review

Abstract

Glycine (Gly) is used as a model system to evaluate the ability of ultrafast two-dimensional infrared (2D-IR) spectroscopy to detect and quantify the low-molecular-weight proteinaceous components of blood serum. Combining data acquisition schemes to suppress absorption bands of H2O that overlap with the protein amide I band with analysis of peak patterns appearing in the off-diagonal region of the 2D-IR spectrum allows separation of the Gly spectral signature from that of the dominant protein fraction of serum in a transmission-mode 2D-IR measurement without any sample manipulation, e.g., filtration or drying. 2D-IR spectra of blood serum samples supplemented with varying concentrations of Gly were obtained, and a range of data analysis methods compared, leading to a detection limit of ∼3 mg/mL for Gly. The reported methodology provides a platform for a critical assessment of the sensitivity of 2D-IR for measuring the concentrations of amino acids, peptides, and low-molecular-weight proteins present in serum samples. We conclude that, in the case of several clinically relevant diagnostic molecules and their combinations, the potential exists for 2D-IR to complement IR absorption methods as the benefits of the second frequency dimension offered by 2D-IR spectroscopy outweigh the added technical complexity of the measurement.

Original languageEnglish
Pages (from-to)920-927
Number of pages8
JournalAnalytical Chemistry
Volume93
Issue number2
Early online date9 Dec 2020
DOIs
Publication statusPublished - 19 Jan 2021

Keywords

  • glycine
  • spectroscopy
  • blood serum

Fingerprint Dive into the research topics of 'Detection of glycine as a model protein in blood serum using 2D-IR spectroscopy'. Together they form a unique fingerprint.

Cite this