Localized Surface Plasmon Coupled Fluorescence Fiber-Optic Biosensor with Gold Nanoparticles

Abstract

A novel fiber-optic biosensor based on a localized surface plasmon coupled fluorescence (LSPCF) system is proposed and developed. This biosensor consists of a biomolecular complex in a sandwich format of <antibody/antigen/Cy5-antibody-gold nanoparticle (GNP)>. It is immobilized on the surface of an optical fiber where a <Cy5-antibody-GNP> complex forms the fluorescence probe and is produced by mixing Cy5-labeled antibody and protein A conjugated gold nanoparticles (Au-PA). The LSPCF is excited by localized surface plasmon on the GNP surface where the evanescent field is applied near the core surface of the optical fiber. At the same time, the fluorescence signal is detected by a photomultiplier tube located beside the unclad optical fiber with high collection efficiency. Experimentally, this novel LSPCF biosensor is able to detect mouse immunoglobulin G (IgG) at a minimum concentration of 1 pg/mL (7 fM) during the biomolecular interaction of the IgG with anti-mouse IgG. The analysis is expanded by a discussion of the amplification of the LSPCF intensity by GNP coupling, and overall, this LSPCF biosensor is confirmed experimentally as a biosensor with very high sensitivity.

Recent advances in plasmonic nanostructures for sensing: a review

“…139,140 Since this time, MEF has experienced a strong growth in biosensing and bioimaging applications, 130,[141][142][143][144][145][146][147] with silver island films remaining the most commonly employed plasmonic nanostructures due to their ability to provide relatively short wavelength visible plasmon absorption bands for small island sizes. Additionally, colloidal silver and gold nanoparticles have also seen significant use over the years for particular applications, where free-floating nanostructures are required (e.g., cellular imaging), 148,[149][150][151] or in filter paper-based MEF substrates that can be used for rapid disposable sample analyses.…”

Plasmonic Nanoparticles and Their Conjugates: Preparation, Optical Properties and Antimicrobial Activity

“…Functionalization of AuNPs with biomolecules other than nucleic acids has also been used in order to develop methodologies suitable for clinical diagnostics. These include: 1) antibodies for signal enhancement in immunoassays [92] ; 2) carbohydrate functionalization to study specific molecular interactions [93] ; and 3) surface functionalization with ligands that can be tailored for specific protein binding [94] or direct binding of peptides and proteins to the Au-nanoparticle surface [95] .…”

Urine Cofilin-1 Detection for Predicting Type 1 Cardiorenal Syndrome in the Coronary Care Unit: A Gold Nanoparticle- and Laser-Based Approach

“…For this purpose, a nanotechnology-based method is suggested to improve the performance in detection accuracy of conventional ELISAs [11,12]. Previously, we successfully reported the feasibility of using a sandwich immunoassay with a gold nanoparticle (GNP)-based localized surface plasmon-coupled fluorescence biosensor (LSPCFB) for detecting proteins in serum at low concentrations and facilitating the identification of diseases [12][13][14][15][16][17].…”

“…Previously, we successfully reported the feasibility of using a sandwich immunoassay with a gold nanoparticle (GNP)-based localized surface plasmon-coupled fluorescence biosensor (LSPCFB) for detecting proteins in serum at low concentrations and facilitating the identification of diseases [12][13][14][15][16][17]. Since it is an essential structural protein, the amount of cofilin-1 may alter when facing stress, and hence the concentration of cofilin-1 in urine may become a potential candidate for detecting AKI as a different structural protein in renal tubule cells [8,9,18].…”