10.1021/nl401522a.s001 Florestan C. Ziem Florestan C. Ziem Nicolas S. Götz Nicolas S. Götz Andrea Zappe Andrea Zappe Steffen Steinert Steffen Steinert Jörg Wrachtrup Jörg Wrachtrup Highly Sensitive Detection of Physiological Spins in a Microfluidic Device American Chemical Society 2013 probe Sensitive Detection technology species Physiological Spins cell biology Sensitivities approach 175 Mn ions analytic ambient conditions imaging ensemble NV sensor relaxation submicrometer length scales center Microfluidic DeviceSensing diffraction manganese chemical 10 ferritin proteins 2013-09-11 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Highly_Sensitive_Detection_of_Physiological_Spins_in_a_Microfluidic_Device/2378134 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.