Nanohole array plasmonic biosensors: Emerging point-of-care applications

Abstract

Point-of-care (POC) applications have expanded hugely in recent years and is likely to continue, with an aim to deliver cheap, portable, and reliable devices to meet the demands of healthcare industry. POC devices are designed, prototyped, and assembled using numerous strategies but the key essential features that biosensing devices require are: (1) sensitivity, (2) selectivity, (3) specificity, (4) repeatability, and (5) good limit of detection. Overall the fabrication and commercialization of the nanohole array (NHA) setup to the outside world still remains a challenge. Here, we review the various methods of NHA fabrication, the design criteria, the geometrical features, the effects of surface plasmon resonance (SPR) on sensing as well as current state-of-the-art of existing NHA sensors. This review also provides easy-to-understand examples of NHA-based POC biosensing applications, its current status, challenges, and future prospects.

Sub‐10 nm Au–Ag Heterogeneous Plasmonic Nanogaps

“…Surface plasmons (SPs), defined as coherent oscillation of conduction electrons on a metal surface under the stimulation of electromagnetic (EM) radiation, can significantly enhance the EM field in the vicinity of metal surfaces,1 which has been widely used in label‐free sensors,2–4 plasmonic color generation,5–7 plasmonic light absorber,8–10 photovoltaic cells,11 and surface‐enhanced Raman scattering (SERS),12–16 etc. To advance the applications, various plasmonic nanostructures have been fabricated to pursue stronger EM fields 15–22.…”

Exploring Graphene and MoS2 Chips Based Surface Plasmon Resonance Biosensors for Diagnostic Applications

“…Therefore, traditional biosensors are not capable to detect low molecular weight of biomolecules because of poor attachment of these biomolecules to the bare metal surface (Maurya and Prajapati, 2016 ). Until now, many methods have been developed to increase the sensitivity of SPR sensor such as using adhesion layer (Agarwal et al, 2016a , b ), metal nanoparticles and nanohole (Prasad et al, 2019 ), metal nanoslits (Yeung et al, 2018 ), and gold nanoparticles (Amendola et al, 2017 ). But until now, precise control over the geometry and optical properties of these nanostructures is still very challenging (Kasani et al, 2019 ).…”

Dual‐Transducer Malaria Aptasensor Combining Electrochemical Impedance and Surface Plasmon Polariton Detection on Gold Nanohole Arrays

“…A nanohole arrays nicknamed as "holey" gold (hAu) electrodes are optically sensitive not only to binding events happening at the surface, [47][48][49] but also to physically adsorbed analyte molecules inside the nanoholes and in the bulk medium. Such detection principle can lead to an extended dynamic detection range beyond the limit of the EIS detection restricted more to the surface binding events.…”