Highly sensitive optical fibre long period grating biosensor anchored with silica core gold shell nanoparticles

Marques, Leonel M.; Hernandez, Francisco U.; James, Stephen W.; Morgan, Stephen P.; Clark, Matt; Tatam, Ralph P.; Korposh, Serhiy

Abstract

An optical fibre long period grating (LPG), modified with a coating of silica core gold shell (SiO2:Au) nanoparticles (NPs) deposited using the layer-by-layer method, was employed for the development of a biosensor. The SiO2:Au NPs were electrostatically assembled onto the LPG with the aid of a poly(allylamine hydrochloride) (PAH) polycation layer. The LPG sensor operates at the phase matching turning point to provide the highest sensitivity. The SiO2:Au NPs were modified with biotin, which was used as a ligand for streptavidin (SV) detection. The sensing mechanism is based on the measurement of the refractive index change induced by the binding of the SV to the biotin. The effect on sensitivity of increasing the surface area by virtue of the SiO2:Au nanoparticles’ diameter and film thickness was studied. The lowest measured concentration of SV was 2.5 nM, achieved using an LPG modified with a 3 layer (PAH/SiO2:Au) thin film composed of SiO2 NPs of 300 nm diameter with a binding constant of

Citation

Marques, L. M., Hernandez, F. U., James, S. W., Morgan, S. P., Clark, M., Tatam, R. P., & Korposh, S. (2016). Highly sensitive optical fibre long period grating biosensor anchored with silica core gold shell nanoparticles. Biosensors and Bioelectronics, 75, https://doi.org/10.1016/j.bios.2015.08.046

• Journal Article Type: Article
• Acceptance Date: Aug 15, 2015
• Online Publication Date: Aug 22, 2015
• Publication Date: Jan 15, 2016
• Deposit Date: Feb 27, 2018
• Publicly Available Date: Feb 27, 2018
• Journal: Biosensors and Bioelectronics
• Print ISSN: 0956-5663
• Electronic ISSN: 0956-5663
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 75
• DOI: https://doi.org/10.1016/j.bios.2015.08.046
• Public URL: https://nottingham-repository.worktribe.com/output/772621
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0956566315303717