Hybrid cavity-coupled plasmonic biosensors for low concentration, label-free and selective biomolecular detection

Abstract

Simple optical techniques that can accurately and selectively identify organic and inorganic material in a reproducible manner are of paramount importance in biological sensing applications. In this work, we demonstrate that a nanoimprinted plasmonic pattern with locked-in dimensions supports sharp deterministic hybrid resonances when coupled with an optical cavity suitable for high sensitive surface detection. The surface sensing property of this hybrid system is quantified by precise atomic layer growth of aluminum oxide using the atomic layer deposition technique. The analyte specific sensing ability is demonstrated in the detection of two dissimilar analytes, inorganic amine-coated iron oxide nanoparticles and organic streptavidin protein. Femto to nanomolar detection limits were achieved with the proposed coupled plasmonic system based on the versatile and robust soft nanoimprinting technique, which promises practical low cost biosensors.

Magnetoplasmons for Ultrasensitive Label-Free Biosensing

“…While the total concentration of IgG found in the adult plasma is about 7 mg/mL, IgG antibodies generated from different infections have significantly lower concentrations at the onset and exhibit unique chemical signatures . This underscores the need for an infection specific detection of IgG at low concentrations with high sensitivity. − Conventionally, antibody detection is done using the techniques like polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), or Western blot that are reliable, however, they are time-consuming processes, prone to contamination, and require high volumes of samples for definitive evaluation. − Alternatively, optical techniques for detection of biomolecules offer the benefits of faster sensing and can be done using a fraction of the sample quantity. − With label-free detection, the concerns of affecting antibody binding affinities and introducing undesired interactions or modifications is eliminated. This removes the restrictions that tag labels such as dyes give, where it can only see the binding at the very end or can potentially modify the sample outside of its’ natural state.…”

Deterministic Nanoassembly of Quasi-Three-Dimensional Plasmonic Nanoarrays with Arbitrary Substrate Materials and Structures

“…Interaction of incident light with three-dimensional (3D) metal–dielectric composite nanoarrays provides unique capabilities to manipulate light at nanoscale length. − Diverse types of 3D or quasi-3D plasmonic nanoarrays with tailored feature shapes, sizes, and configurations have been explored for a broad range of light-driven sensors and actuators such as imagers, biosensors, lasers, and antennas. − Traditionally, the construction of 3D plasmonic nanoarrays has largely relied on the use of nanolithography techniques by exploiting either electron-beam lithography (EBL), or focused ion-beam lithography (FIB), or interference lithography (IL), but their laborious, complex, and time-consuming nature impedes practical applications. − In addition, the nanolithography processes often require the use of thermal and chemical treatments, leading to additional increase of complexity and risk in protecting the substrate materials. Alternative strategies involve the use of micro/nanoscale 3D printing techniques such as nanoimprinting and modular microtransfer printing, allowing for deterministic integration of 3D plasmonic nanoarrays with a foreign receiver substrate, and thereby circumventing the incompatibility of the nanolithography conditions with substrate materials. − Nevertheless, the choice of receiver substrates remains limited by the required physical contact forces during printing steps, yielding an increased risk of potential damages to receiver substrates particularly composed of mechanically fragile materials and structures.…”

DNA-Modified Plasmonic Sensor for the Direct Detection of Virus Biomarkers from the Blood

“…In this work, we demonstrate a cavity-coupled plasmonic biosensor integrated with a microfluidic blood plasma separator − to detect the DENV biomarker directly from blood as schematically shown in Figure a. The cavity coupling improves the quality factor Q (bandwidth, Δλ) of the LSP resonance while large area parallel nanoimprinting-based patterning ensures deterministic resonance replication (λ R ). , In order to make it target specific, the plasmonic biosensor is functionalized with a high-affinity single stranded DNA (ssDNA) aptamer against the nonstructural NS1 protein from DENV2 serotype, Figure b.…”

“…The plasmonic sensor used in this work is formed by hybridizing the LSP resonance (LSPR) with an asymmetric Fabry–Perot cavity resonator. ,, The plasmonic nanostructure, unlike conventional one metallic element, is composed of two complementary elements, hole/disk, of period/diameter of 560/200 nm and separated by 350 nm relief depth. The pattern is thermally embossed on UV curable epoxy SU-8 and coated with 30 nm of gold, see Figure a (inset).…”