Technique - (14) Surface-enhanced Raman spectroscopy (SERS)

Type: Experimental

Description: Plasmonic nanostructure-enhanced Raman scattering for single-molecule chemical identification and label-free biosensing.

Department(s)/lab(s): Physics (Cavendish Laboratory) | NanoPhotonics Centre @ Cambridge
Summary:

Baumberg directs the NanoPhotonics Centre, confining light into sub-nanometre plasmonic 'picocavities' between metal nanostructures to achieve single-molecule-sensitive SERS and study light-matter coupling at the molecular scale. Current work spans low-cost healthcare biosensors, chiral nanophotonics and quantum coherent effects in plasmonic cavities.

Department(s)/lab(s): School of Physics (joint with Electrical and Electronic Engineering) | Crozier Nanophotonics Laboratory @ UMelb
Summary:

Crozier holds a joint Physics/Electrical Engineering chair and runs a nanophotonics laboratory spanning plasmonic and dielectric metasurfaces, on-chip optical trapping and manipulation of nanoparticles and cells, mid-infrared spectroscopy and detection with metasurface-enhanced and colloidal-nanocrystal devices, and light emission from 2D semiconductors. The unifying theme is engineering the local optical density of states to increase the signal available from a very small number of emitters or molecules. Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — the plasmonic and dielectric antenna work is the same physics used to raise photon collection efficiency and hence the shot-noise floor of NV-ensemble magnetometers operating at pT/sqrt(Hz). Note: a substantial fraction of the group's output is device fabrication rather than sensitivity-limited measurement, which is a caveat against the stated preference.

Department(s)/lab(s): Physics (Cavendish Laboratory) | Physics for Sustainable Chemistry Group @ Cambridge
Summary:

De Nijs leads the Physics for Sustainable Chemistry group, studying light-matter interactions at molecular length-scales using plasmonic nanocavities, with applications spanning single-molecule SERS sensing, in-situ electrochemical monitoring, and plasmon-driven photocatalysis for green chemistry (e.g. plastics degradation).

Department(s)/lab(s): Chemistry – Photon Science Institute | Gardner Group (Analytical and Biomedical Spectroscopy) @ Manchester
Summary:

Gardner's group develops infrared and Raman microspectroscopy for biomedical diagnostics and disease sensing. Research directions: (1) FTIR synchrotron microspectroscopy — using Diamond Light Source synchrotron IR beam for high-spatial-resolution chemical mapping of biological tissues for cancer diagnosis; (2) Raman microspectroscopy — label-free chemical imaging of cells and tissue for disease classification using machine-learning chemometrics; (3) SERS probes — developing gold nanoparticle SERS labels for targeted cancer biomarker detection; (4) Breathomics — on-chip photonic sensors for exhaled breath analysis for early disease detection. The infrared and Raman methods provide label-free molecular sensing with potential for quantum-enhanced sensitivity.

Department(s)/lab(s): School of Chemistry | Gooding Biosensors and Surface Chemistry Group @ UNSW
Summary:

Gooding is one of the world's most-cited biosensor scientists (inaugural editor-in-chief of ACS Sensors) and runs a group of over thirty researchers spanning surface chemistry, electrochemistry and nanomedicine. The sensing programme that matters here is the move from ensemble to digital, single-molecule-resolved detection: nanoparticle-tethered electrochemical sensors in which single binding events are counted rather than averaged, nanopore blockade sensors for protein biomarkers such as PSA, amplification-free nucleic-acid detection, and antifouling surface chemistries that make any of this work in real biological fluid. He has a strong commercialisation record (AgaMatrix glucose sensors). Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — his single-molecule-counting philosophy is the biosensing analogue of moving from a pT/sqrt(Hz) NV ensemble to single-spin detection: in both cases the sensitivity gain comes from resolving individual events rather than improving an averaged signal. He is also the obvious collaborator for anyone trying to functionalise a diamond or nanoparticle quantum sensor for a real analyte.

Department(s)/lab(s): Physics & Astronomy – Photon Science Institute | Graham Group (SERS and Nanoplasmonic Biosensing) @ Manchester
Summary:

Graham's group develops SERS-based nanoplasmonic sensing platforms for biomedical applications. Research directions: (1) SERS nanogap substrates — engineering colloidal gold and silver nanostructure clusters with reproducible, high-enhancement nanogaps for single-molecule SERS detection; (2) In vivo SERS — intravenous SERS nanotags for tumor imaging and multiplexed biomarker detection in living organisms; (3) Microfluidic SERS — integrating SERS probes in microfluidic channels for continuous monitoring of circulating biomarkers; (4) Quantitative SERS — calibration strategies for absolute analyte quantification for clinical diagnostics. Extreme sensitivity (single-molecule) relevant to quantum-enhanced optical sensing.

Department(s)/lab(s): School of Chemistry | Hutchison Molecular Polaritonics Group @ UMelb
Summary:

Hutchison works on molecular polaritonics: what happens to chemistry when molecular electronic or vibrational transitions are strongly coupled to a confined optical mode in a Fabry-Perot or plasmonic nanocavity. He was among the first to show that vibrational strong coupling modifies ground-state chemical reactivity, and the group continues to probe polariton-modified energy transfer, photochemistry and transport, alongside single-molecule spectroscopy and 2D-material photonics. Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — the connection to quantum sensing is the cavity: the same Purcell and collective-coupling physics that concentrates optical density of states around a molecule is what is used to improve photon collection and readout fidelity in NV ensembles operating at pT/sqrt(Hz). This is fundamental light-matter physics with a clear nonclassical-state angle.

Department(s)/lab(s): Chemistry | Jain Lab @ UIUC
Summary:

Studies molecular and nano-optics, plasmonics, and near-field light-matter interactions, using super-resolution optical imaging to reveal active sites and phase transformations in heterogeneous catalysis and single nanodomains.

Department(s)/lab(s): Chemistry | Link Lab @ UIUC
Summary:

Studies photophysics and photochemistry of plasmonic nanomaterials using single-particle optical imaging and ultrafast spectroscopy, with applications to solar energy conversion.

Department(s)/lab(s): School of Chemistry / Bio21 Institute | Mulvaney Nanoscience Laboratory @ UMelb
Summary:

Mulvaney directs the ARC Centre of Excellence in Exciton Science and runs Melbourne's nanoscience laboratory. The group's distinctive capability is single-particle and single-emitter optical spectroscopy: photon-antibunching and blinking statistics from individual quantum dots and perovskite nanocrystals, photothermal and dark-field spectroscopy of individual metal nanoparticles, and the electrochemical control of single-nanocrystal charge state. Applications run from LEDs and solar cells to quantum-dot probes for single-particle tracking in cells. Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — his single-emitter photon-statistics measurements share the shot-noise-limited photon-counting methodology of NV-ensemble ODMR readout, and the group's nanocrystal probes are direct competitors/complements to nanodiamond in cellular sensing. Large, well-resourced group.