Study on the immobilization of hemoglobin by nano mesoporous MCFs and its optical properties

Abstract

Nano mesoporous molecular sieve MCFs (mesocellular foams) was synthesized successfully through hydrothermal method. Then bovine hemoglobin was successfully immobilized into the mesoporous molecular sieve MCFs, the immobilized enzyme was 50.27 mg g−1. The desirable adsorbate/adsorbent, Hb/MCFs, (mass ratio, m/m) for 3/50 was achieved by adjusting adsorption conditions. The obtained materials were characterized using various techniques such as the powder XRD, Fourier transform infrared spectroscopy, UV–Vis solid diffuse reflectance spectroscopy (SDRS), photoluminescence spectrum and N2 adsorption desorption study at 77 K. The results showed that hemoglobin had been immobilized successfully inside the channels of mesoporous MCFs. Scanning electron microscopy was used to confirm the average particle diameters of MCFs-Hb and (CH3-MCFs)-Hb. And the results showed that the average particle diameters of MCFs-Hb and (CH3-MCFs)-Hb were 2212 ± 50 nm and 2219 ± 50 nm, respectively. The adsorption process of MCFs/(CH3-MCFs) adsorbing hemoglobin enzyme was in accordance with pseudo-second-order kinetic equation. The process of MCFs/(CH3-MCFs) adsorbing hemoglobin enzyme belonged to an exothermic reaction which was a spontaneous reaction. Freundlich model described the adsorption of hemoglobin by MCFs/CH3-MCFs well. The desorption process of MCFs-Hb/(CH3-MCFs)-Hb composite was studied in the sodium hydroxide solution (0.1 mol L−1), and equilibrium was reached at 5 h. The desorption rates were 72.58% and 69.67%, respectively. The luminescence spectra showed that the obtained composites had the light-emitting properties.