Plasmon-Based Label-Free Biosensor Using Gold Nanosphere for Dengue Detection

Hafiz Zeeshan Mahmood,Asim Jilani,Javed Iqbal,Yasir Javed,Swelm Wageh,Sami Ullah,Sajid Farooq,Yasir Jamil

doi:10.3390/cryst11111340

Abstract

In this study, a novel label-free immunosensor platform is developed to exploit the localized surface plasmon resonance (LSPR) phenomenon. The LSPR solution-based platform is designed by a gold nanospheres probe, functionalized with monoclonal anti-dengue antibody (IgG). Numerical calculations are performed to assess the LSPR extinction spectrum and spatial near electric field distribution around the nanoparticle surface. Important parameters that govern sensor performance, molecular and refractive index sensitivity are evaluated. On the evaluation of the platform as a molecular sensor, the detection of dengue NS1 antigens is presented. The results are consistent with the numerical simulations, which depicts the system’s ability to identify dengue NS1 antigen concentrations as low as 0.07 ± 0.01 µg/mL, along with fosters its potential application in plasmonic sensing.

Highlights

Optical properties of noble metallic nanoaggregates have been a rigorously studied subject, which stimulated the interest of the researchers due to their fascinating plasmonic characteristics which depend on the geometry of the nanostructure [1,2]
Dengue virus is primarily examined through clinical symptoms and confirmed through laboratory tests, such as immunoglobulin G (IgG), immunoglobulin M (IgM), enzyme linked immunosorbent assays (ELISA), point of care tests and reverse transcription polymerase chain reactions
We investigated both the experimental and theoretical approach based on the evaluation of the spatial field distribution and field enhancement around the nanoparticles’ surface, as well as the attachment of the biomolecule

Summary

Introduction

Optical properties of noble metallic nanoaggregates have been a rigorously studied subject, which stimulated the interest of the researchers due to their fascinating plasmonic characteristics which depend on the geometry of the nanostructure [1,2]. Label-free biosensing does not require labels to facilitate measurements. Instead, it exploits the intrinsic physical properties of the analytes (e.g., molecular weight, dielectric permittivity, refractive index, size, charge, electrical impedance) to detect their presence in a sample. Label-free biosensing techniques have made tremendous progress in recent years, due to their rapid and economical biomolecule detection ability in small reaction volumes. They lend themselves for integration into lab-on-chip platforms, and allow real time monitoring of the concentration of target analytes [8]

Methods

Results

Discussion

Conclusion