Characterization of Nanoclay-phosphatase Complex with IR Spectroscopy and Electron Microscopy

Commercial phosphatase enzyme (acid and alkaline) was immobilized with different nanoclays collected from three genetically different soil orders (i.e. Inceptisol, Vertisol and Alfisol) and complexes were characterized by IR spectroscopy and electron microscopy in the laboratory. Scanning electron microscopy (SEM) images showed modification of surface morphologies of nanoclay due to phosphatase adsorption (appearance of boulder like structures and rough surfaces after immobilization). IR scanning confirmed presence of characteristic band of clay mineral due to H-O-H, Si-O stretching and Al-O-H bending in all nanoclays. Nanoclay-phosphatase complexes were also characterized by means of IR and it was found that carbonyl (C=O) amide III (−CO-N-) and amide I (−CO-NH2) group present in various amino acid side chains were involved in adsorption process whereas carboxylate, primary amine and amide II (−CO-NH-) groups present in glutamine became more free on adsorption.