Label‐Free Near‐Infrared Plasmonic Sensing Technique for DNA Detection at Ultralow Concentrations

Abstract

Biomolecular detection at a low concentration is usually the most important criterion for biological measurement and early stage disease diagnosis. In this paper, a highly sensitive nanoplasmonic biosensing approach is demonstrated by achieving near-infrared plasmonic excitation on a continuous gold-coated nanotriangular array. Near-infrared incident light at a small incident angle excites surface plasmon resonance with much higher spectral sensitivity compared with traditional configuration, due to its greater interactive volume and the stronger electric field intensity. By introducing sharp nanotriangular metallic tips, intense localization of plasmonic near-fields is realized to enhance the molecular perception ability on sensing surface. This approach with an enhanced sensitivity (42103.8 nm per RIU) and a high figure of merit (367.812) achieves a direct assay of ssDNA at nanomolar level, which is a further step in label-free ultrasensitive sensing technique. Considerable improvement is recorded in the detection limit of ssDNA as 1.2 × 10 −18 m based on the coupling effect between nanotriangles and gold nanoparticles. This work combines high bulk-and surface-sensitivities, providing a simple way toward label-free ultralow-concentration biomolecular detection.

Electrochemiluminescent nanostructured DNA biosensor for SARS-CoV-2 detection

“…In particular, DNA biosensors offer a possibility of SARS-CoV-2 detection based on its genetic code. Despite there are some bibliography describing DNA biosensors, it is an area of great interest and its potential applications are still at its beginnings [ [6] , [7] , [8] , [9] ] [ [6] , [7] , [8] , [9] ] [ [6] , [7] , [8] , [9] ]. Among the different types of biosensor transduction, electrochemiluminescence (ECL) is a very attractive technique which has reach great interest in the last years and consists on recording the light emitted by species in the excited state, which have been generated at electrodes through high-energy electron transfer reactions, when they return to the ground state [ 10 ].…”

Near-infrared tunable surface plasmon resonance sensors based on graphene plasmons via electrostatic gating control

“…52 The selected recent literatures on DNA detection by SPR manner since 2019 are listed in Table 2. Although the LOD has been improved further, [54][55][56][57] a notable feature is the need to use gold nanoparticles or nanorods as sensitivity enhancement strategy.…”

Plasmonic Biosensor Augmented by a Genetic Algorithm for Ultra-Rapid, Label-Free, and Multi-Functional Detection of COVID-19

“… 28 Therefore, infrared plasmonic biosensors are excellent candidates for real-time, label-free detection of trace analytes. Recently, many plasmonic biosensors have been reported, and they are widely used to detect chemical and biological molecules, such as gases, 29 , 30 nucleic acids, 31 and proteins. 32 The various sensing applications of infrared plasmonic sensors have brought new inspiration for virus detection.…”