Surface-enhanced Raman spectroscopy of γ-aminobutyric acid on silver colloid surfaces

Abstract

The surface‐enhanced Raman spectroscopy (SERS) of γ‐aminobutyric acid (GABA) adsorbed on silver colloids in H2O and D2O were recorded and analyzed. When the concentration is greater than 10−3 M, the adsorbed species is the anionic form of the amino acid that interacts with the surface through both functional groups. According to the vibrational interpretation of the spectra, it is assumed that at concentrations in the order of or less than 10−3 M, GABA undergoes chemical transformations, which increase upon dilution, and spectra are recorded that are the result of the competitive adsorption between the amino acid in its anionic form and the products resulting from the chemical transformations. © 1997 John Wiley & Sons, Inc. Biospectroscopy 3: 449–455, 1997

Surface‐enhanced Raman scattering of 3‐phenylpropionic acid (hydrocinnamic acid)

“…33 Figure 3 shows the SERS spectrum of 3-phenylpropionic acid obtained by subtracting the spectrum in Fig. 2(b) from that in Fig.…”

Adsorption of aspartic acid on kaolinite

“…Several different mechanisms have been proposed for the adsorption of amino acids to oxide surfaces, including electrostatic interactions [6,9], hydrogen bond formation [2], ligand-exchange [4] and ion-exchange [1] reactions, and specific interactions of both carboxyl and amino groups [10].…”

Detection of amino acid neurotransmitters by surface enhanced Raman scattering and hollow core photonic crystal fiber

“…It further suggests that concentration of GLU in the range 10 -7 M can be detected, which is several orders of magnitude lower as compared to the detection limit of GLU reported earlier by SERS methods. 7,8 Similar experiments were performed with various mixtures of GABA as described above for GLU. Although, sharing a similar chemical structure, the SERS spectrum of GABA was spectrally less rich in comparison of GLU.…”

“…[1][2] However, these methods are time-consuming and expensive. In contrast, optical techniques such as surface enhanced Raman scattering (SERS) have gained popularity as a rapid tool for characterizing biological sample mixtures [3][4][5][6][7][8][9] . This is mainly due to its high degree of molecular specificity as well as sensitivity along with the ease of operation and cost-efficiency.…”

“…The amplification in the Raman signal results from the enhancement of the 'localized electromagnetic field' on the surface of nanoparticles. 3 Recently, SERS has been used for monitoring the concentration of various neurotransmitters including dopamine, norepinephrine, GABA, GLU etc in their bulk solutions [4][5][6][7][8][9] Furthermore, the dichroic filter also acted as a high pass filter for the light scattered backward from the sample, thus allowing only the Raman wavelength to pass through it. The filtered Raman light was then imaged onto a fiber bundle (Fiberoptic System Inc., 26 multimode fiber, NA= 0.22) by another 6.3x microscopic objective lens (L3) with N.A as ~0.20.…”