Microplasma-Engineered Ag/GONR-Based Nanocomposites for Selective and Label-Free SERS-Sensitive Detection of Dopamine
Huin-Ning Huang, Shang‐Yu Wang, Wei‐Hung Chiang
Abstract
The rapid, sensitive, and selective detection of dopamine (DA) is important for diagnosing brain diseases and drug development. However, traditional methods for DA detection are usually time-consuming, expensive, and with low sensitivity and selectivity. Here, we present microplasma synthesis of Ag/graphene oxide nanoribbon (GONR) nanocomposites for the selective and label-free surface-enhanced Raman scattering (SERS) detection of DA using rhodamine 6G (R6G) as the standard Raman reporter. The plasma synthesis enables fabrication of Ag/GONR nanocomposites via one-step synthesis and deposition of the Ag nanoparticles (NPs) on the surfaces of GONRs. The plasma-synthesized Ag/GONR nanocomposites show superior SERS performance toward the sensitive nanomolar-level detection of DA with a low limit of detection (LoD) of 0.67 nM. Moreover, it is possible to achieve a broad linear detection range from 5 to 2500 nM of DA with high selectivity based on the interference test. Our study suggests that the exceptional SERS performance can be due to the synergistic effect of Ag-induced electromagnetism (EM) and a GONR-assisted chemical enhancement mechanism (CM) that existed in the synthesized Ag/GONR nanocomposites. Our work not only provides a method for the selective and label-free SERS detection of DA but also a direction for other emerging SERS-related applications including catalysis, biosensing, and optoelectronics.