RESUMO
A M13 virus based SERS nanoprobe is presented. Gold nanocubes closely aligned into chains along the length of the virus intensify Raman signals of various reporter molecules serving as specific labels. An antibody is expressed at one end to detect the analyte. This new SERS nanoprobe holds promise for infinitesimal and multiplexed detection of any antigen.
Assuntos
Bacteriófago M13/ultraestrutura , Ouro/química , Imunoensaio/instrumentação , Nanopartículas Metálicas/ultraestrutura , Impressão Molecular/métodos , Análise Espectral Raman/instrumentação , Bacteriófago M13/química , Desenho de Equipamento , Análise de Falha de Equipamento , Nanopartículas Metálicas/química , Ressonância de Plasmônio de Superfície/instrumentação , Propriedades de SuperfícieRESUMO
A Fiber-Optic Localized Surface Plasmon Resonance (FO LSPR) sensor was fabricated using spherical gold nanoparticles (Au NPs) on a flattened end-face of the optical fiber. The Au NPs were easily synthesized by the Turkevich method and were immobilized on the end-face of the optical fiber by using a self-assembled monolayer (SAM). In order to examine the possibility of its application as a biosensor for label-free immunoassays, the fabricated FO LSPR sensor was used for the detection of the antibody-antigen reaction of interferon-gamma (IFN-γ) and the limit of detection (LOD) was approximately 2pg/ml. Herein, The antibodies and bovine serum albumins (BSAs) were immobilized on the Au NPs by physisorption. Also, the FO LSPR sensor was used for the detection of a prostate-specific antigen (PSA) and the LOD was 1pg/ml below. The fabricated FO LSPR sensor can be used for real-time label-free immunoassay having fast detection time, high resolution and sensitivity. In addition, the proposed sensor platform has the advantages of low cost, simple optical setup, remote sensing, simple fabrication, real-time detection, low sample volume, and potential application to in-vivo detection systems.
Assuntos
Imunoensaio/instrumentação , Interferon gama/análise , Antígeno Prostático Específico/análise , Ressonância de Plasmônio de Superfície/instrumentação , Anticorpos Imobilizados/imunologia , Reações Antígeno-Anticorpo , Desenho de Equipamento , Ouro/química , Humanos , Interferon gama/imunologia , Limite de Detecção , Masculino , Nanopartículas/química , Nanopartículas/ultraestrutura , Antígeno Prostático Específico/imunologiaRESUMO
Localized surface plasmon resonance (LSPR) occurs when nanoparticles are bound to the surface of a sensor which is sensitive to the refractive index of the surrounding medium. The sensitivity of the sensor is highly dependent on the type of nanoparticles and their size, density and shape. Using an optical fiber as a sensor has various advantages, such as guided signal delivery and low energy loss. In this study, a Fiber-optic localized surface plasmon resonance (FO-LSPR) sensor was developed and the sizes of the gold nanoparticles (Au NPs) used therein were controlled by reduction with chloroauric acid. The extinction cross-section was calculated by the Mie theory to examine the dependence of the resonance intensity and sensitivity of the fabricated FO-LSPR sensor on the size and density of the Au NPs situated on its end-face. In order to use it as a biosensor, the fabricated FO-LSPR sensor was used to detect the biotin-streptavidin interaction.
