| Year | 2018 |
|---|---|
| Journal Info. | Sensors & Actuators B, 255, 183-192 (2018) |
| Author | Ahmed Ali, Eun Young Hwang, Jaebum Choo and Dong Woo Lim* |
| etc. |
Abstract
Surface-enhanced Raman scattering (SERS) has been of great interest to advance sensitive optical biosen-sors. Clustered metallic nanoparticles as SERS nanoprobes are important to detect specific biomoleculeswith ultra-sensitivity. We report herein that the cluster formation of gold nanoparticles (GNPs) wasinduced by nanoscale graphene oxides (NGOs) with 120 nm to develop a new class of SERS nan-otags for biosensing. The GNPs with 4-mercaptopyridine as a Raman reporter were modified with1-pyrenemethylamine to introduce hydrophobic moieties on the surfaces and were complexed withNGOs via noncovalent interactions of - stacking and van der Waals interactions, resulting in the for-mation of NGO-GNP clusters (NGO-GNPCs). The NGO-GNPCs increased the SERS signal 3- to 4-fold higherthan that of the individual GNPs due to enhancement of the electromagnetic field at the interstices ofthe GNPs. As a proof of concept, the NGO-GNPCs as SERS nanoprobes and magnetic beads (MBs) weredeveloped to detect immunoglobulin G (IgG). Sandwich-type immunocomplexes of the NGO-GNPCs, IgG,and MBs were formed, representing a linear correlation between Raman intensity and IgG concentration,and a limit of detection of 0.6 pM. It suggests that the NGO-GNPCs as SERS nanoprobes could open a newavenue for highly sensitive SERS-based biosensing.
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