Nanoscale graphene oxide-induced metallic nanoparticle clustering for surface-enhanced Raman scattering-based IgG detection

• Published in: Sensors and actuators. B, Chemical Chemical, 2018-02, Vol.255, p.183-192
• Main Authors: Ali, Ahmed, Hwang, Eun Young, Choo, Jaebum, Lim, Dong Woo
• Format: Article
• Language: English
• Subjects: Beads; Biomolecules; Biosensors; Clustering; Clusters; Electromagnetic fields; Gold; Graphene; Graphite; IgG detection; Interstices; Metallic nanoparticles; Nanoparticles; Nanoscale graphene oxide; Nanostructured materials; Raman spectra; Surface enhanced Raman scattering
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2017.07.140

The NGO-interfaced GNPCs was developed as a new class of SERS nanoprobes for biosensing applications. [Display omitted] •Cluster formation of gold nanoparticles (GNPs) was induced by nanoscale graphene oxide (NGO) to develop the SERS nanotag.•The NGO-interfaced GNP clusters increased the SERS signal 3- to 4-fold higher than that of the individual GNPs.•The SERS signal of the immunocomplexes was linearly correlated with IgG concentration.•The LOD value of IgG was 0:6 pM which is lower than that obtained from the other detection techniques. Surface-enhanced Raman scattering (SERS) has been of great interest to advance sensitive optical biosensors. Clustered metallic nanoparticles as SERS nanoprobes are important to detect specific biomolecules with ultra-sensitivity. We report herein that the cluster formation of gold nanoparticles (GNPs) was induced by nanoscale graphene oxides (NGOs) with 120nm to develop a new class of SERS nanotags for biosensing. The GNPs with 4-mercaptopyridine as a Raman reporter were modified with 1-pyrenemethylamine to introduce hydrophobic moieties on the surfaces and were complexed with NGOs via noncovalent interactions of π-π stacking and van der Waals interactions, resulting in the formation of NGO-GNP clusters (NGO-GNPCs). The NGO-GNPCs increased the SERS signal 3- to 4-fold higher than that of the individual GNPs due to enhancement of the electromagnetic field at the interstices of the GNPs. As a proof of concept, the NGO-GNPCs as SERS nanoprobes and magnetic beads (MBs) were developed 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 new avenue for highly sensitive SERS-based biosensing.