Quantum-based sensing of biomolecules using fluorescent nitrogen vacancy-center nanodiamonds

A. Rampersaud, I. Rampersaud, C. Fletcher, M. Slocum, L. Drummy
Columbus Nanoworks,
United States

Keywords: sensors, NV-center, nanodiamonds, DNA, proteins, diamond magnetometry, flow cell


Diamond magnetometry exploits spin-dependent photoluminescence of nitrogen-vacancy center nanodiamonds (FNDs) to detect weak magnetic fields at room temperature, with nanoTesla sensitivities. Changes in FND fluorescence, due to the presence of a magnetic field, can be monitored by an all-optical technique termed optically detected magnetic resonance (ODMR). We received Direct-to-Phase II SBIR funding from the Air Force to use diamond magnetometry to detect positional changes in magnetic nanoparticles, relative to FNDs, during nucleic acid hybridization or protein binding. We have fabricated 50 nm FNDs and built an optical system for ODMR. Our optical setup employs a custom-designed flow cell which can be used to monitor FND fluorescence in fluids such as saliva, blood, and urine. We demonstrate the use of the flow cell for ODMR by capturing biotinylated magnetic particles using FND-streptavidin conjugates that are attached to glass coverslips within the flow cell body. Continued development of this technology will lead to rapid and accurate detection of biological threats, pathogens, primary disease biomarkers, and other healthcare problems.