title: Highly sensitive detection of physiological spins in a microfluidic device.
abstract: Sensing and imaging paramagnetic species under physiological conditions is a key technology in chemical and biochemical analytics, cell biology, and medical sciences. At submicrometer length scales, nitrogen-vacancy (NV) centers in diamond offer atom-sized probes for magnetic fields. We show that spin relaxation of an ensemble NV sensor allows sensing of adsorbed and freely diffusing manganese(II) ions and adsorbed ferritin. Sensitivities approach 175 Mn ions and 10 ferritin proteins per diffraction limited spot under ambient conditions.
authors.affiliation: 3rd Institute of Physics and Research Center SCOPE, University Stuttgart , Stuttgart 70569, Germany.
authors.forename: Florestan C
authors.initials: FC
authors.lastname: Ziem
authors.forename: Nicolas S
authors.initials: NS
authors.lastname: Götz
authors.forename: Andrea
authors.initials: A
authors.lastname: Zappe
authors.forename: Steffen
authors.initials: S
authors.lastname: Steinert
authors.forename: Jörg
authors.initials: J
authors.lastname: Wrachtrup
mesh_terms: D018130:Diamond / Q000737:chemistry*; D005293:Ferritins / Q000737:chemistry; D006801:Humans; D060526:Magnetic Fields; D008345:Manganese / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D009584:Nitrogen / Q000737:chemistry*
chemical_list: D008345:Manganese; D018130:Diamond; D005293:Ferritins; D009584:Nitrogen