Ultra‐Sensitive Graphene‐Plasmonic Hybrid Platform for Label‐Free Detection

Abstract

A graphene‐Au nano‐pyramid hybrid system that enables label‐free single molecule detection is demonstrated. The bio‐compatible graphene‐based SERS platform boosts a high density of hot spots with local SERS enhancement factor over 1010. We demonstrate that graphene can play a key role in quantitative study of SERS mechanisms, and can also serve as a promising building block in SERS active structures especially for biosensor applications.

Label-Free SERS Selective Detection of Dopamine and Serotonin Using Graphene-Au Nanopyramid Heterostructure

“…Third, chemical interaction between graphene and target molecules results in selective enhancement and/or prohibition of certain SERS modes. 18 The unique feature of biochemical finger-printing of Raman spectroscopy, which greatly reduces false-positive detection combined with the capability of quantitative measurement makes the hybrid SERS platform a rare and very powerful experimental technique in biomedical research and clinical applications especially for brain activity mapping. We show in this work that the graphene-Au tip hybrid platform is capable of detecting dopamine and serotonin at 10 −9 M level in simulated body fluids supplemented with background serum proteins with the lowest detectable molecular concentration reaching 10 −10 M in deionized water.…”

Plasmon-driven reaction controlled by the number of graphene layers and localized surface plasmon distribution during optical excitation

“…In a graphene-mediated SERS (G-SERS) substrate [13][14][15][16][17][18] ; the monolayer graphene (1G) provides an atomically flat surface for Raman enhancement. Because the graphene surface is chemically inert, signals from G-SERS substrates have great advantages over normal SERS by providing cleaner vibrational information free from various metal-molecule interactions (molecules cannot interact with the chemically active metal by graphene-mediated interactions) and being more stable against photo-induced damage 13 .…”

“…Because the graphene surface is chemically inert, signals from G-SERS substrates have great advantages over normal SERS by providing cleaner vibrational information free from various metal-molecule interactions (molecules cannot interact with the chemically active metal by graphene-mediated interactions) and being more stable against photo-induced damage 13 . Furthermore, the ultrasensitive graphene-plasmonic hybrid platform for label-free SERS detection is approaching single-molecule detection 18 .…”

A Review on Applications of Two-Dimensional Materials in Surface-Enhanced Raman Spectroscopy

“…The graphene electrons involvement in the Raman scattered process can enhance the electron-phonon coupling and thus induce the enhancement of the Raman signals. When a vibrational mode involves the lone pair or electrons, which has stronger coupling with graphene [20,39], the vibrational mode with particular molecular orientations could have highest Raman enhancement, following the SERS selection rules. For example, CuPc molecule will be in lying-down position after annealing, which results in a molecular orientation that isoindole group is in parallel with graphene surface.…”

“…Two-dimensional (2D) materials, such as graphene and molybdenum disulfide (MoS 2 ), have unique electronic and optical properties and thus attract wide interests in their potential applications in electronic devices, sensors, and energy generation [13][14][15][16][17][18]. In addition to the above-mentioned applications, graphene and other 2D materials have also been explored to enhance Raman signals [13,[19][20][21][22]. Since the discovery of graphene's Raman enhancement capability [23], extensive researches have been done to reveal the enhancing mechanism of twodimensional materials, as well as their application in Raman enhancement either with bare 2D material substrate or with hybrid metal/2D material substrate [24][25][26][27].…”