No abstract

Entrapment of glucose oxidase (GOx) enzyme in a new reverse micelle emulsion system was studied. The microemulsion consists of aqueous phase (buffered enzyme)/SPAN 85/n-decane. Critical micelle concentration (CMC) of surfactant-SPAN 85 in n-decane was determined using dynamic light scattering study and it was used to develop microemulsion system. Most stable and optically transparent microemulsion with entrapped glucose oxidase showed higher values of specific enzyme activity, maximum reaction rate (Vmax) and turn over number and low value of Michaelis-constant (Km) in comparison to homogeneous GOx (enzyme-glucose oxidase) system. The microemulsion system was successfully used to quantify D-glucose in lipid based food products without any sample preparation. Comparison of these results with chemical method (phenol-sulfuric acid method) and commercial kit method used in food industry validate the efficiency of the new proposed system. The study provides new information about the glucose content of some commonly consumed milk based products where nutritional labels do not accurately show true glucose content. These findings provide support for comprehensive glucose labeling to food products commonly used by the children.

Synthesis of horseradish peroxidase-gold nanoparticle conjugates (HRP-AuNPs) has been studied for the development of biofunctionalized gold nanoparticles (AuNPs) through biogenic route. Herein, horseradish peroxidase enzyme has been used to synthesize gold nanoparticles at room temperature in tricine buffer. The morphology and size distribution of HRP-AuNPs conjugates were obtained by different techniques including dynamic light scattering (DLS), UV-visible (UV-vis) spectrophotometry, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The enzyme activity of HRP-AuNP conjugate was compared with free enzyme to determine their catalytic efficiency. The results suggests that HRP-AuNP conjugates are monodisperse particles with average hydrodynamic diameter of 83.93 ± 2.1 nm, zeta potential of about -18.4 ± 1.1 mV and higher enzyme activity towards H2O2 as compared to free horseradish peroxidase. These biofunctionalized gold nanoparticles could act as tag or labeling agent for various applications.