Khadijeh Eskandari - Nanobiotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
Hedayatollah Ghourchian - Laboratory of Microanalysis, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
Aghdas Banaei - Research Institute of Applied Science, Academic Center of Education, Culture and Research (ACECR), Shahid Beheshti University, Tehran, Iran

A feasible and fast method for Adult Hemoglobin (A-Hb) and Fetal Hemoglobin (F-Hb) study was developed by immobilization of Hb on gold-coated magnetic iron oxide nanoparticles (GMNPs).The prepared GMNPs composite nanoparticles with 60 nm diameter were used as a carrier for the immobilization of Hb. The A-Hb and F-Hb were physically attached to the GMNPs nanoparticles. The direct electroche- mistry of F-Hb and A-Hb showed a quasi-reversible cyclic voltammogram corres- ponding to the Heme group with a formal potential of 314 and -334 mV in 0.1M PBS (pH 6.2), respectively. The apparent charge transfer rate constant (ks) and transfer coefficient (α) for electron transfer between the electrode surface and pro- tein were calculated as 0.29/s and 0.1 for F-Hb and 0.21/s and 0.47 for A-Hb. The linear concentration rangesare17.3–225 and 7.4-53 mM for F-H band A-Hb biosensors for H O detection. The lifetime of biosensor is more than 2 weeks.

Biosensor, Direct Electrochemistry, H2O2, Gold-coated, Iron Oxide Nanoparticles, Hemoglobin