Glucose oxidase from asperigillus niger

Polyamide substrates (pore size – 200nm, thickness – 60μm) were obtained from GE Healthcare Life Sciences (Piscataway, NJ, USA). The linker molecule dithiobis succinimidyl propionate (DSP), dimethyl sulfoxide (DMSO), and 1X phosphate buffered saline (PBS) were purchased from Thermo Fisher Scientific Inc. (Waltham, MA, USA). Salt-free streptavidin from Streptomyces avidiini (≥ 13 units/mg protein), alcohol oxidase enzyme from Pichia pastoris (10–40 units/mg protein), glucose oxidase from Asperigillus niger (100,000–250,000 units/g), D-(+)- glucose, absolute ethyl alcohol (≥ 99.5%) were purchased from Sigma- Aldrich (St. Louis, MO, USA). Long arm NHS- biotin was purchased from Vector laboratories (Burlingame, CA, USA). Glucose oxidase antibody was obtained from Abcam (Cambridge, MA, USA). Glucose oxidase antibody was diluted in 1X PBS. Streptavidin was lyophilized in 1X PBS and biotin was dissolved in DMSO. Alcohol oxidase enzyme was biotinylated using the protocol stated in Du et. al (Du et al., 1996 ). Synthetic sweat was prepared as per the recipe described in M.T. Mathew et. al (Mathew et al., 2008 ). The pH range was varied by varying the concentrations of the constituents. Single donor human sweat of pH ~6 was purchased from Lee Biosolutions Inc. (Maryland Heights, MO, USA). No preservatives were added to this product and it was stored at −20°C.