Low detection limits using sandwich and inhibition assays on long-range surface plasmon waveguide biosensors

Sarkar

ACS Appl. Mater. Interfaces

2020

Surface plasmon resonance-based sensors have emerged as commercially fostering portable biodetectors. The scientific community is engaged in extensive research to improve their performance in terms of sensitivity, selectivity, and reproducibility for the recognition of specific biomolecules. Essentially, there is a need for miniaturizing the size of existing sensors with innovative designs without compromising their bioaffinity and sensitivity performance. In this work, we propose and demonstrate a gratingcoupled surface plasmon polariton (SPP) sensor on a thin flat gold layer using a hybrid configuration. The proof of concept of the grating architecture has been realized through an innovative fabrication procedure, with experimental verification of its bulk sensitivity. The geometry is identical to the prismcoupling configuration, yet with miniaturization and compactness. Characteristics of the excited modes in the spectral regime of interest are investigated using the finite-difference time-domain simulations. The effective index calculation of the resonance conditions and the accompanying field distribution can identify the excited SPP and metal-assisted guided-mode resonance modes. Detailed probing of the electric field distribution of the desired SPP mode reveals an extended evanescent decay length of 1284 nm, close to the theoretical limit, and an extended propagation length of 270 μm. The experimental demonstration of the reflectance dip with two different analyte media perceived an increased bulk sensitivity of 1133 nm/RIU. Remarkably, this resonant mode exhibits sensing capabilities for a wide range of analyte refractive indexes. We believe that the fabricated configuration with observed high sensitivity and calculated ultradeep evanescent field penetration depth along with extended propagation length can lead to the designing of a hands-on biochip for detecting large biomolecules.

Section: ■ Introductionsupporting

confidence: 85%

Grating-Coupled Surface Plasmon-Polariton Sensing at a Flat Metal–Analyte Interface in a Hybrid-Configuration

Sarkar

ACS Appl. Mater. Interfaces

2020

Optical Sensing and Detection VII

“…Besides, more elaborated strategies of functionalization (sandwich, inhibition, competitive) could be explored to enhance the performance currently achieved, as demonstrated on long-range surface plasmon waveguide biosensors in the article [173].…”

Section: Discussionmentioning

confidence: 99%

Development of a new plasmonic transducer for the detection of biological species

Laffont

Crespo‐Monteiro

Berini

et al. 2022

During the COVID-19 outbreak, PCR tests were widely used for large-scale testing and screening.Yet, this technique requires bulky and time-consuming procedures to prepare the samples collected from the patients before their analysis by well-trained experts with expensive and specific equipment. PCR is therefore not competitive as a technique of detection for a widespread and rapid use in point-of-care sites. Thus, the COVID-19 pandemic highlighted the need for cheap and easy-to-implement biosensors. Surface plasmon resonance based sensors were suggested as a promising alternative in recent years. Indeed, they enable real-time and label-free detection of a wide range of analytes. That explains their widespread use in various fields of applications such as pharmacology, toxicology, food safety, and diagnosis. This thesis proposes and demonstrates a new plasmonic configuration of detection, which can address challenges posed by point-of-care settings. The gratings used as transducers in this configuration were fabricated based on laser interference lithography combined with a nanoimprinting process. The responses of these nanostructures interrogated by a p-polarized light beam result in a transfer of energy between two diffracted orders over an angular scan. This optical phenomenon termed as "optical switch", was theoretically and experimentally investigated and optimized.The principle of detection based on this specific configuration was demonstrated for the detection of small variations in the bulk refractive index with solutions comprised of different ratios v Abstract of de-ionized water and glycerol. A limit of detection in the range of 10 −6 RIU was achieved.In addition, preliminary bio-assays obtained by combining this configuration with a functionalization are presented and demonstrate the selectivity and the potential of this new plasmonic configuration for biosensing applications. This thesis work paves the way for the use of the optical switch configuration as a biosensor aligned with low-cost manufacturing and relevant for diagnosing in point-of-care sites. vi List of Figures 1.4 Sketches of the sequential steps for an ELISA assay consisting in detecting and quantifying gentamicin (red Y). A solution with a high gentamicin concentration results in a clearer solution than a solution with a low gentamicin concentration. That manifests through a lower (resp. higher) absorbance for high (resp. low) gentamicin concentrations, as shown in Figure 1.3. These sketches are extracted from [23].

Laser & Photonics Reviews

“…[30][31][32] The electromagnetic field generated by LSPR is firmly confined to the surface of metal nanoparticles, therefore, the electric field on the surface of the metal particle is significantly stronger than the electric field far away from the metal particle. LRSPR [33][34][35][36][37][38][39] is an improvement of the traditional SPR. In general, a medium buffer layer is added between the fiber core and the metal film (as shown in Figure 1c).…”

Section: Spr Lspr and Lrsprmentioning

confidence: 99%

Research Progress of Resonance Optical Fiber Sensors Modified by Low‐Dimensional Materials

Wang

Yin

et al. 2023

Resonance optical fiber sensors are widely studied for their high sensitivity, small size, and anti-electromagnetic interference. However, traditional resonance optical fiber sensors have encountered bottlenecks in the trace detection due to limited localized field intensity and low molecules affinity. With the development of materials technology, low-dimensional materials such as quantum dots, graphene, and transition metal sulfides have excellent properties such as high carrier mobility, large specific surface area, and flexible structure controllable artificial technologies that can also be used to synthesize new materials with desired characteristics, which can enhance the performance of sensors fundamentally. The introduction of low-dimensional materials can not only achieve the performance optimization of sensors, but also make sensors functional to realize the diversification of detection objects. This paper reviews the research progress of resonance optical fiber sensors based on low-dimensional materials. The detection principle and performance indexes related to resonance optical fiber sensing are elaborated, and resonance optical fiber sensors modified by low-dimensional materials are introduced. Furthermore, the role of low-dimensional materials in resonance fiber sensing is summarized, the direction of performance optimization in the production process of resonance fiber sensors is analyzed, and the future prospect of new resonance optical fiber sensors is given.