Extrinsic surface-enhanced Raman scattering detection of influenza A virus enhanced by two-dimensional gold@silver core–shell nanoparticle arrays. Issue 100 (13th October 2016)

• Record Type: Journal Article
• Authors: Karn-orachai, Kullavadee; Sakamoto, Kenji; Laocharoensuk, Rawiwan; Bamrungsap, Suwussa; Songsivilai, Sirirurg; Dharakul, Tararaj; Miki, Kazushi
• Is Part Of: RSC advances. Volume 6:Issue 100(2016)
• Page Start: 97791
• Page End: 97799
• Publication Date: 2016-10-13
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra17143e
• Languages: English
• ISSNs: 2046-2069

Abstract

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. Abstract : A surface-enhanced Raman scattering (SERS) based biosensor using a direct immunoassay platform is demonstrated for influenza A detection. The nucleoprotein of influenza A virus, which is one of the most conserved and abundant structural proteins on the virion, was used as a target. In this study, highly sensitive biosensors were realized by combining specific recognition of antibody–antigen interactions and high signal enhancement of the SERS effect. SERS probes were fabricated by decorating PEGylated, 4, 4′-thiobisbenzenethiol (TBBT)-labeled gold nanoparticles (NPs) with influenza A antibodies. To improve the sensitivity, a SERS immunoassay was performed on two-dimensional (2D) arrays of gold@silver core–shell (Au@Ag) NPs, which work as SERS substrates. The SERS signal of TBBT was utilized to detect the selective nucleoprotein–antibody recognition. The SERS signal was enhanced ∼4 times by using the SERS substrates instead of a flat Au film. These results indicate that using a well-tuned Au@Ag 2D array as a SERS substrate is an effective way of improving sensitivity of SERS-based biosensors. Our SERS immunoassay system revealed high selectivity and good reproducibility with a sample-to-sample variation of 4.6% (relative standard deviation). To demonstrate the applicability of our SERS immunoassay system to real biological samples, the detection of influenza A using infected allantoic fluid was also performed. The linear relation between the concentration of infected allantoic fluid and the SERS signal was obtained in the range of 5 to 56 TCID50 per mL ( R 2 = 0.96 for the TBBT Raman bands at 1565 cm −1 ) with the lowest detection limit of 6 TCID50 per mL. These findings demonstrated the potential of this SERS immunosensor platform for the highly sensitive and specific detection of target molecules in a complex matrix commonly found in clinical specimens.