Extrinsic surface-enhanced Raman scattering detection of influenza A virus enhanced by two-dimensional gold@silver core–shell nanoparticle arrays

Kullavadee Karn-orachai,Rawiwan Laocharoensuk,Kenji Sakamoto,Kazushi Miki,Sirirurg Songsivilai,Tararaj Dharakul,Suwussa Bamrungsap

doi:10.1039/c6ra17143e

Abstract

A surface enhanced Raman scattering (SERS) based biosensor using a direct immunoassay platform was demonstrated for influenza A detection. The sensitivity was improved ~4 times by using a well-tuned Au@Ag 2D array instead of a flat Au film.

Highlights

Surface enhanced Raman scattering (SERS) is regarded as a powerful technique for detecting trace amounts of biological and chemical substances[1,2] adsorbed on metal nanostructures,[3] because of its inherent advantages: e.g. nondestructive, no photobleaching, sensitive and fast detection.[4,5] Highly sensitive biosensors for clinical and early diagnosis of diseases can beFor extrinsic detection methods, target biomolecules are rst immobilized on a substrate, and SERS probes containing Raman reporter molecules are selectively labeled on the target biomolecules
Target biomolecules are rst immobilized on a substrate, and SERS probes containing Raman reporter molecules are selectively labeled on the target biomolecules
By designing metallic NPs properly, the scattering efficiency of Raman reporter molecules can be strongly enhanced via localized surface plasmon resonance (LSPR) of the metallic NPs

Summary

Introduction

Surface enhanced Raman scattering (SERS) is regarded as a powerful technique for detecting trace amounts of biological and chemical substances[1,2] adsorbed on metal nanostructures,[3] because of its inherent advantages: e.g. nondestructive, no photobleaching, sensitive and fast detection.[4,5] Highly sensitive biosensors for clinical and early diagnosis of diseases can beFor extrinsic detection methods, target biomolecules are rst immobilized on a substrate, and SERS probes containing Raman reporter molecules are selectively labeled on the target biomolecules. Paper outer surface.[8,9] By designing metallic NPs properly, the scattering efficiency of Raman reporter molecules can be strongly enhanced via localized surface plasmon resonance (LSPR) of the metallic NPs. Typically SERS-based immunosensors rely on the use of at substrates, e.g. Au or glass substrates.[10,11] In those cases, the enhancement of Raman signals solely comes from the LSPR of isolated SERS probe and/or plasmon coupling among SERS probes. By properly designing SERS substrates, an additional Raman signal enhancement can be expected through strong plasmon coupling between the SERS substrate and SERS probes According to these strategies, some groups reported good achievements in SERS biosensors on the nanostructurebased substrate, for example, two-dimensional (2D) array of Au nanotriangle,[15] Au–Ag coated GaN substrate,[12] and 2D array of Au nanostar,[13] with high sensitivity and/or low detection limit. The development of SERS substrates that can be electromagnetically coupled with SERS probes is essential to realize highly sensitive biosensors

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Conclusion