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.

Kuhlmey works on structured electromagnetic materials across an unusually wide frequency range: microstructured optical fibres, metamaterials, non-reciprocal and time-varying media, and — the newest and most sensing-relevant thread — quantum terahertz photonics, in collaboration with ENS Paris and CSIRO. The THz programme is explicitly aimed at single-photon/single-electron coupling in the THz band, which if it works would allow quantum devices to operate at a few kelvin rather than millikelvin. The group runs a THz time-domain spectroscopy lab with cryogenic capability. 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 THz band is the one part of the spectrum where neither superconducting circuits nor NV ensembles currently offer quantum-limited detection, so this is a genuine gap-filling programme rather than a variation on existing pT/sqrt(Hz) approaches.