Development of dip-strip sucrose sensors: Application of plant invertase immobilized in chitosan-guar gum, gelatin and poly-acrylamide films

作者：Bagal Kestwal Dipali^*; Kestwal Rakesh Mohan; Chiang Been Huang; Karve Meena S

来源：Sensors and Actuators B: Chemical , 2011, 160(1): 1026-1033.

DOI：10.1016/j.snb.2011.09.021

• Enzyme dip-strip
• Sucrose
• Spectrophotometry
• Chitosan-guar gum invertase (ChG-INV)
• Poly-acrylamide invertase (PAA-INV)
• Gelatin invertase (GEL-INV)

In 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 vulgar's) 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 x 10(-8) M, while poly-acrylamide invertase dip-strip and gelatin-invertase strip had same limit of detection of 1 x 10(-7) M for sucrose. All three dip-strip systems showed concentration dependent response for sucrose in the range of 1 x 10(-7)-1 x 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.

• 出版日期2011-12-15