Terahertz identification and quantification of neurotransmitter and neurotrophy mixture

Abstract

Terahertz spectroscopy has been widely used for investigating the fingerprint spectrum of different substances. For cancerous tissues, the greatest difficulty is the absorption peaks of various substances contained in tissues overlap with each other, which are hard to identify and quantitative analyze. As a result, it is very hard to measure the presence of cancer cell and then to diagnose accurately. In this paper, we select three typical neurotransmitters (γ-aminobutyric acid, L-glutamic acid, dopamine hydrochloride) and two typical metabolites (inositol and creatine) in neurons to measure their terahertz spectra with different mixture ratios. By choosing characteristic absorption peaks, removing baseline and using the least square method, we can identify the components and proportions of each mixture, where the goodness of fit to practical situation is up to 94%. These results provide important evidences for identifying nerve substances and obtaining exact quantitative analysis.

Broadband terahertz recognizing conformational characteristics of a significant neurotransmitter γ-aminobutyric acid

“…They found that the formation of a GABA-BA cocrystal under slow solvent evaporation is affected by the pH value of the aqueous solution. Peng et al 22 researched two typical metabolites and three typical neurotransmitters, including GABA, from 0.9 to 4.5 THz by FTIR and successfully identied the components and proportions of a mixture consisting of neurotransmitters and neurotrophic substances. These works provide useful characteristics of GABA in the THz region and the tentative assignments of its modes.…”

Label-free sensing of the binding state of MUC1 peptide and anti-MUC1 aptamer solution in fluidic chip by terahertz spectroscopy

“…Recent developments in terahertz (THz, 0.1-10 THz) biomedical applications have garnered much interest in label-free research, owing to its unique spectral advantages [14][15][16][17]. THz photon energy meshes well with the energy levels of low-frequency molecular motions including rotation, vibration, and relative translation of the molecular skeleton, and particularly the hydrogen bonds between biomolecules and water [18].…”

Isomers Identification of 2-hydroxyglutarate acid disodium salt (2HG) by Terahertz Time-domain Spectroscopy

“…A THz time-domain spectroscopy (THz-TDS) system was used 15 . In our experiments, 800 nm femtosecond laser characterized by pulse duration of 100 fs, repetition rate of 76 MHz, and average power of 150 mW was used.…”

“…Pump beam modulated by optical chopper was focused on a Gallium Arsenide (GaAs) and then emitted THz wave. The diverging THz beam was collected and focused by paraboloidal mirrors to pass though biological samples, and then the probe beam was used to detect THz wave with samples’ physical properties by photoconductive antennas( ) 15 – 17 . For our experimental system, the effective bandwidth for the measured signals is from 0.2 to 2.5 THz, the spectrum resolution is better than 15 GHz, signal to noise radio (SNR) is larger than 1000:1.…”

“…Terahertz (THz) spectroscopy has been widely known due to its high penetrability, low ionization energy, fingerprint spectrum and coherence. In recent decades, THz spectroscopic technique has proved its effectiveness in detection of skin, breast, tongue, liver, colon tumors 12 – 14 and also the mixtures identification 15 . Here, in this paper, we expect to realize the spectral detection and the accurate identification of L-2HG and D-2HG basing on the terahertz time-domain spectroscopy.…”