Hemoglobin (Hb) immobilized on amino-modified magnetic nanoparticles for the catalytic removal of bisphenol A

Catalytic removal of bisphenol A from aqueous solution with hemoglobin immobilized on amino-modified magnetic nanoparticles as an enzyme catalyst was reported. The amino-modified magnetite nanoparticles were firstly prepared by the coprecipitation of Fe(2+) and Fe(3+) with NH(3)·H(2)O and then modified by 3-aminopropyltriethoxysilane. The immobilization process was optimized by examining enzyme concentration, glutaraldehyde concentration, cross-link time, and immobilization time. The optimum conditions for the removal of bisphenol A with immobilized hemoglobin were also investigated. Under the optimality conditions, the removal efficiency of bisphenol A was about 80.3%. The immobilization had a beneficial effect on the stability of hemoglobin and conversions of bisphenol A. According to the proposed breakdown pathway and the intermediates, the enzyme-catalytic removal of bisphenol A by the immobilized hemoglobin is considered to be an effective method.