TY - JOUR
T1 - A Vertical Flow Method for Sensitive Raman Protein Measurement in Aqueous Solutions
AU - Li, Shu-Chi
AU - Hiramatsu, Hirotsugu
PY - 2019/8/6
Y1 - 2019/8/6
N2 - Raman scattering is intrinsically faint. Raman spectroscopy would be more valuable with improvements in the signal detection efficiency. To improve the signal detection efficiency, we propose a vertical flow method, which is a derivative of the liquid core optical fiber technique employed for sensitive Raman signal detection. In the vertical flow method, the sample solution flows from a pinhole to prepare a liquid column wrapped with air and uses total reflection at the sample−air interface to confine the excitation beam and Raman signal. The Raman signal emerges from the pinhole for efficient collection. This method enhanced Raman signal intensity by up to 90 times. When measuring a bovine serum albumin aqueous solution, the limit of detection (LOD) was 0.029 ± 0.003 mg mL−1 (0.44 ± 0.05 μM). We discuss the signal enhancement factor dependence on several parameters in the vertical flow method. Our method provides a simple technique to improve Raman spectroscopy sensitivity using universal materials.
AB - Raman scattering is intrinsically faint. Raman spectroscopy would be more valuable with improvements in the signal detection efficiency. To improve the signal detection efficiency, we propose a vertical flow method, which is a derivative of the liquid core optical fiber technique employed for sensitive Raman signal detection. In the vertical flow method, the sample solution flows from a pinhole to prepare a liquid column wrapped with air and uses total reflection at the sample−air interface to confine the excitation beam and Raman signal. The Raman signal emerges from the pinhole for efficient collection. This method enhanced Raman signal intensity by up to 90 times. When measuring a bovine serum albumin aqueous solution, the limit of detection (LOD) was 0.029 ± 0.003 mg mL−1 (0.44 ± 0.05 μM). We discuss the signal enhancement factor dependence on several parameters in the vertical flow method. Our method provides a simple technique to improve Raman spectroscopy sensitivity using universal materials.
U2 - 10.1021/acs.analchem.9b01472
DO - 10.1021/acs.analchem.9b01472
M3 - Article
C2 - 31256586
VL - 91
SP - 9806
EP - 9812
JO - Analytical Chemistry
JF - Analytical Chemistry
SN - 0003-2700
IS - 15
ER -