Nanosilver-embedded silicon nanowires as a SERS-active substrate for the ultrasensitive detection of monoamine neurotransmitters

Quantification of Plasma Dopamine in Depressed Patients Using Silver-Enriched Silicon Nanowires as SERS-Active Substrates

“…In addition, the typical DA peaks remain unaffected in the presence of AA. This observation aligns with previous research, indicating that Raman spectra of DA in solution are stabilized due to the inhibition effect of AA on the oxidation of DA. , …”

“…This discrepancy may come from the formation of hydrogenbonding complexes or interactions between the silver surface and C−O groups of DA. 46,78,79 Figure 4b−d shows the linear correlations between the concentration of standard DA and specific peaks at 1156, 1284, and 1516 cm −1 (i.e., −log C vs peak height), respectively. The peak at 1156 cm −1 in the standard solution was also observed in the Raman spectra of DA in both ethanol and serum samples, but was not observed in the Raman spectrum of NE.…”

“…In contrast to the reflectance observed in its untreated counterpart, SiNWs@Ag subjected to HNO 3 treatment exhibited an overall decrease in reflectance. The decrease of reflectance intensity was attributed to the removal of Ag aggregates from the top layer by the HNO 3 treatment . However, it cannot be ruled out that there is a possibility of an increased conversion of incident photons into localized surface plasmons …”

“…Notably, the DA peak attributed to C–O stretching vibrations shows an average discrepancy of 8.33 cm –1 between powder (1290 cm –1 ) and solution states (ethanol = 1290 cm –1 , serum = 1274 cm –1 , extracted plasma = 1284 cm –1 ). This discrepancy may come from the formation of hydrogen-bonding complexes or interactions between the silver surface and C–O groups of DA. ,, …”

Synchronous Fe3+-Enhanced Colorimetric and Liquid SERS-Based Detection of Dopamine Using Core–Shell Plasmonic Nanoparticles

“…Figure a shows that the DA (250 μM) solution and DA-free SERS substrate did not exhibit Raman signals; the Raman spectrum of DA in the CSNP dispersion showed more distinguishable signals in the magnified Raman spectra in the range of 1000–1800 cm –1 , but they were quite weak and noisy. However, DA in the CSNPs/Fe 3+ sensing system exhibited strong Raman signals that displayed some characteristic peaks of DA at 1610, 1481, 1388, and 1266 cm –1 , which correspond to benzene ring stretching, CH 2 bending scissors, NH twisting, and C–O stretching, respectively. − That is, the Raman signals of DA in the CSNPs/Fe 3+ solution were significantly enhanced primarily owing to the Fe 3+ -enhanced aggregation of CSNPs, which can generate strong localized electric fields ( hot spots ) in the SERS measurement. The dominant peak at 1388 cm –1 in the SERS spectrum of DA was chosen to identify the DA analyte.…”