Immobilization of a-amylase was carried out by ionic exchange and hydrophobic interactions on gold nanorods (GNRs) synthesized via sequential seed mediated growth method. The optimum temperature of alpha-amylase increased from 50 to 60 degrees C and its optimum pH was shifted from 6 to 7 upon immobilization. The kinetic parameters, K-m and V-max values were 3 mg/ml and 6.4 mu m min(-1) for free and 3.4 mg/ml and 5.91 mu m min(-1) for immobilized enzymes, respectively. The immobilization process brought significant enhancement of stability to temperature and extreme pH values with respect to free alpha-amylase. Enzyme shows higher functionality than the free form when incubated for long time (1 h) at 80 degrees C and at extreme pH values (3 and 10). In addition to improving thermal stability, the storage stability of alpha-amylse exhibited a significant increase upon immobilization which makes it a biocatalyst of possible industrial application, specially a potential candidate for production of glucose syrups on industrial scale. (C) 2015 Elsevier Ltd. All rights reserved.