Bagal-Kestwal D.Kestwal R.M.Chiang B.H.Karve M.S.2019-07-112019-07-11201109254005https://scholars.lib.ntu.edu.tw/handle/123456789/413295In present work, chitosan, guar gum, gelatin and poly-acrylamide hydrogels were tested for plant invertase immobilization. Acid invertase was extracted and partially purified from watermelon fruit (Cirullus vulgaris) with specific activity of 834 units mg-1. Immobilization of invertase was carried out in composite matrices of chitosan-guar gum, gelatin and poly-acrylamide with immobilization efficiency of 93%, 85% and 74% respectively. Scanning electron microscope analysis of blank and immobilized enzyme films was carried out to reveal their surface morphology. Enzyme dip-strips were designed to evaluate sucrose concentration from different aqueous samples. Response time for chitosan-guar gum invertase, gelatin invertase and poly-acrylamide invertase dip-strips was found to be 7, 10 and 12 min, respectively. Detection limit for sucrose using chitosan-guar gum invertase dip-strip was 1 ¡Ñ 10 -8 M, while poly-acrylamide invertase dip-strip and gelatin-invertase strip had same limit of detection of 1 ¡Ñ 10-7 M for sucrose. All three dip-strip systems showed concentration dependent response for sucrose in the range of 1 ¡Ñ 10-7-1 ¡Ñ 10-3 M. Operational stability and storage stability for the sensors were checked after each use. The dip-strips were also employed for sucrose estimation from sugar factory samples. The results concluded that the designed dip-strips ensure fast and easy detection of sucrose with good accuracy and reliability. ? 2011 Elsevier B.V. All rights reserved.Chitosan-guar gum invertase (ChG-INV)Enzyme dip-stripGelatin invertase (GEL-INV)Poly-acrylamide invertase (PAA-INV)SpectrophotometrySucrosejournal article10.1016/j.snb.2011.09.0212-s2.0-81155134371https://www.scopus.com/inward/record.uri?eid=2-s2.0-81155134371&doi=10.1016%2fj.snb.2011.09.021&partnerID=40&md5=3d9648aa6f4b0cf1f1bcbcd8a73839b0