Spread spectrum SERS allows label-free detection of attomolar neurotransmitters

Abstract

The quantitative label-free detection of neurotransmitters provides critical clues in understanding neurological functions or disorders. However, the identification of neurotransmitters remains challenging for surface-enhanced Raman spectroscopy (SERS) due to the presence of noise. Here, we report spread spectrum SERS (ss-SERS) detection for the rapid quantification of neurotransmitters at the attomolar level by encoding excited light and decoding SERS signals with peak autocorrelation and near-zero cross-correlation. Compared to conventional SERS measurements, the experimental result of ss-SERS shows an exceptional improvement in the signal-to-noise ratio of more than three orders of magnitude, thus achieving a high temporal resolution of over one hundred times. The ss-SERS measurement further allows the attomolar SERS detection of dopamine, serotonin, acetylcholine, γ-aminobutyric acid, and glutamate without Raman reporters. This approach opens up opportunities not only for investigating the early diagnostics of neurological disorders or highly sensitive biomedical SERS applications but also for developing low-cost spectroscopic biosensing applications.

Single Step Laser-Induced Deposition of Plasmonic Au, Ag, Pt Mono-, Bi- and Tri-Metallic Nanoparticles

“…Plasmonic nanoparticles are a matter of intense current research in many scientific directions connected with the development of synthetic procedures [ 1 , 2 ], various applications in electrochemistry and catalysis [ 3 , 4 , 5 ], phase contrast in bioimaging [ 6 ], and metal-enhanced fluorescence (MEF) [ 7 ]. Plasmonic nanoparticles are widely used in surface-enhanced Raman scattering (SERS) [ 8 ] and variants of SERS such as spread spectrum SERS (ss-SERS) [ 9 ], plasmon-enhanced stimulated Raman scattering (PESRS) microscopy with single-molecule detection sensitivity [ 10 ], catalyzing processes with real-time SERS monitoring [ 11 ], etc. The key feature of plasmonic NPs appears in the interaction between metal nanoparticles and electromagnetic waves and leads to free electron oscillations known as localized surface plasmon resonance (LSPR).…”

Ultrathin-shell epitaxial Ag@Au core-shell nanowires for high-performance and chemically-stable electronic, optical, and mechanical devices

“…In addition to the SPP characterization, surface plasmon resonance (SPR) is another essential characterization technique for AgNW based plasmonic devices intended for SERS applications, which enable label-free, nondestructive, highsensitivity chemical analysis [66,67]. One concern of using Ag@Au core-shell nanowires in SERS sensing applications is whether the Au shell will introduce extra background due to its fluorescence under 532 nm excitation, the most popular SERS excitation wavelength.…”

Applications of Surface-Enhanced Raman Scattering in Biochemical and Medical Analysis

“…On the one hand, such a classification is not definite, and it is hard to say if this could ever be possible. On the other hand, SERS is one of the most sensitive techniques for detecting compounds, such as neurotransmitters at the attomolar level, and has significant advantages over routine methods (Lee et al, 2021b). The label-free detection of the dengue virus in blood samples is also an impressive example of a fast SERS-based procedure that requires only a very small sample (5 µl) (Gahlaut et al, 2020).…”