Label‐Free Near‐Infrared Plasmonic Sensing Technique for DNA Detection at Ultralow Concentrations. Issue 23 (19th October 2020)

• Record Type: Journal Article
• Authors: Chen, Shimeng; Liu, Chuan; Liu, Yun; Liu, Qiang; Lu, Mengdi; Bi, Sheng; Jing, Zhenguo; Yu, Qingxu; Peng, Wei
• Is Part Of: Advanced science. Volume 7:Issue 23(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-19
• Subjects: biosensing -- nanostructure -- plasmonic sensors -- signal enhancement -- ultrasensitivity; Science -- Periodicals; 505
• DOI: 10.1002/advs.202000763
• Languages: English
• ISSNs: 2198-3844

Abstract

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. Abstract : A highly sensitive nanoplasmonic biosensing approach is reported by achieving near‐infrared plasmonic excitation on a continuous gold‐coated nanotriangular array. This sensor possesses an enhanced sensitivity of 42 103.8 nm per RIU and a high figure of merit of 367.812. This technical approach is used to detect single‐stranded DNA hybridization adsorption events by using gold nanoparticles and achieves an estimated detection limit of 1.2 × 10 −18 m .