posted on 2024-02-14, 22:07authored byYoungju Gwon, Jong-Hoon Kim, Sang-Wha Lee
A decrease in the levels of dopamine (DA)a key
catecholamine
biomarker for major depressive disorderhighlights the need
for quantitative analysis of biological fluids to aid in the early
diagnosis of diverse neuropsychiatric disorders. This study developed
silicon nanowires enriched with silver nanoparticles to serve as a
surface-enhanced Raman scattering (SERS) substrate to enable precise
and sensitive quantification of blood plasma DA levels in humans.
The silver-enriched silicon nanowires (SiNWs@Ag) yielded flower-like
assemblies with densely populated SERS “hot spots,”
allowing sensitive DA detection. By correlating DA concentration with
Raman intensity at 1156 cm–1, the plasma DA levels
in treatment-naïve patients with major depression (n = 18) were 2 orders of magnitude lower than those in healthy
controls (n = 18) (6.56 × 10–10 M vs 1.43 × 10–8 M). The plasma DA concentrations
differed significantly between the two groups (two-tailed p = 5.77×10-7), highlighting a distinct
demarcation between depression patients and healthy controls. Furthermore,
the SiNWs@Ag substrate effectively differentiated between DA and norepinephrine
(NE) in mixtures at nanomolar levels, demonstrating its selective
detection capability. This study represents the first report on the
quantitative detection of DA levels in human blood samples from individuals
with major depression using an SERS technique, emphasizing its potential
clinical utility in the evaluation and diagnosis of neuropsychiatric
disorders.