Water dispersible and biologically important molecule dehydroascorbic acid (DHA, capable to cross the blood brain barrier) coated Fe3O4 superparamagnetic nanoparticles having an average size of similar to 6 nm were synthesized through one pot aqueous coprecipitation method under atmospheric air. An antioxidant ascorbic acid (AA) used in the synthesis oxidized itself to dehydroascorbic acid (DHA) to consume dissolved or available oxygen in reaction mixture which died away the oxidative impact of atmospheric air and formed DHA encapsulated the Fe3O4 nanoparticles which stabilized the Fe3O4 nanoparticles and significantly enhanced their colloidal solubility in water. Fe3O4 phase, superparamagnetic property. DHA coating and stable colloidal solubility in water were confirmed by means of XPS, VSM, IR and zeta potential analysis respectively. T-1, T-2 and T-2 weighted magnetic resonance imaging (MRI) and corresponding relaxivity (r(1) = 0.416, r(2) = 50.28 and r(2)=123.65 mM(-1) and r(2)/r(1) = 120.86, r(2)/r(1) = 297.23) of colloidally dispersed DHA-coated nanoparticle water phantom revealed a strong contrast enhancement in T-2 and T-2 weighted images. The compatibility of DHA-coated Fe3O4 nanoparticles toward human blood cells was examined by means of cell counting and cell morphological analysis with the use of optical microscope and scanning electron microscope imaging. (C) 2014 Elsevier Inc. All rights reserved.