en Radiation Biology Radiation Biology گزارش کوتاه Short Report <p><strong>Background:</strong> Hydrogen peroxide (H2O2), produced by gamma ray irradiation to watery solution, was used as an analytical parameter for dosimetry of cobalt-60 (60Co) radiation. <strong>Materials and Methods:</strong> Detection of the produced H₂O₂ was carried out using two methods: an amperometric biosensor fabricated by immobilization of anthraquinone 2-carboxylic acid modified horseradish peroxidase on glassy carbon electrode, and chemiluminescence technique using luminol as a fluorophore and diperiodatocuprate as a catalyst. <strong>Results:</strong> In the first method, at the applied potential of -550 mV (vs. Ag/AgCl) the biosensor showed the sensitivity of 74.46 nA/Gray and detection limit of 0.061 Gray (R.S.D=3.67% for N=3) towards H₂O₂ produced by ⁶⁰Co. In the second method, the sensitivity and detection limit for ⁶⁰Co gamma ray was determined to be 2.34 (luminescence intensity/Gray) and 0.069 Gray (R.S.D=4.16% for N=3), respectively. <strong>Conclusion:</strong> The obtained results revealed that both proposed techniques, with leaner range from 0.25 to 5 Grays are applicable for detection and dosimetry of gamma ray from ⁶⁰Co.</p> Cobalt-60, gamma ray, hydrogen peroxide, electrochemistry, chemiluminescence 377 382 http://ijrr.com/browse.php?a_code=A-10-1-532&slc_lang=en&sid=1 M. Shourian 790031947532846009468 790031947532846009468 No Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran, Iran H. Ghourchian hadi@ibb.ut.ac.ir 790031947532846009469 790031947532846009469 Yes Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran, Iran