Production of bio-ink
Enzyme solutions were prepared using dry samples and certain buffers.
0.15 g of glucose oxidase (GOD) (15000 U / L) were dissolved in 50 ml
TRIS buffer, pH 7.4 for glucose biosensor. 0.15 g of cholesterol oxidase
(CHOD) (300 U / L) were dissolved in 50 ml potassium phosphate buffer,
pH 6.8 for cholesterol biosensor. Using ethylene glycol the viscosity of
both enzymes solutions was adjusted to 10 cP.