Directed Microwave-Assisted Self-Assembly of Au–Graphene–Au Plasmonic Dimers for SERS Applications

Ghosh, P and Paria, D and Balasubramanian, K and Ghosh, A and Narayanan, R and Raghavan, S (2019) Directed Microwave-Assisted Self-Assembly of Au–Graphene–Au Plasmonic Dimers for SERS Applications. In: Advanced Materials Interfaces, 6 (18).

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Abstract

Noble metal dimers with sub-nanometer separation support strong electromagnetic field enhancement which has practical applications in surface enhanced Raman scattering (SERS), photodetection, and photocatalysis. Monolayer graphene is an excellent spacer material to practically realize uniform separation between the dimers. Here, directed microwave-assisted self-assembly of Au nanoparticle dimers is reported, separated by graphene monolayer over 1 cm2 substrates. Detailed analytical models of Au particle formation kinetics explain the experimentally observed control of the density and selectivity of the dimer formation. SERS substrates with 7 × 106 cm−2 of Au–Graphene–Au dimers are obtained which yield a 35-fold increase in the Raman spectral signal of graphene from a single dimer, and an enhancement factor in intensity per molecule of 107 allows ppb level detection of Rhodamine 6G. A system of such dimers can provide an efficient, reliable, and inexpensive solution for many nanophotonic applications that require ultrahigh field confinement, such as SERS and photodetection.

Item Type:	Journal Article
Publication:	Advanced Materials Interfaces
Publisher:	Wiley-VCH Verlag
Additional Information:	The copyright for this article belongs to Wiley-VCH Verlag.
Keywords:	Electromagnetic fields; Gold nanoparticles; Graphene; Monolayers; Nucleation; Photodetectors; Plasmonics; Precious metals; Raman scattering; Self assembly; Separation; Substrates; Surface scattering, Electromagnetic field enhancement; Enhancement factor; Microwave assisted; Microwave synthesis; Plasmonic dimers; Ppb level detection; Surface enhanced Raman Scattering (SERS); Ultra-high fields, Dimers
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	07 Jan 2023 05:16
Last Modified:	07 Jan 2023 05:16
URI:	https://eprints.iisc.ac.in/id/eprint/78850

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