Alkaline phosphatase based amperometric biosensor immobilized by cysteamine-glutaraldehyde modified self-assembled monolayer.

Alkaline phosphatase (ALP) was immobilized with cross-linking agents glutaraldehyde and cysteamine by forming a self-assembled monolayer on a screen printed gold electrode. ALP converts p-nitrophenyl phosphate to p-nitrophenol and phosphate. p-Nitrophenol loses H(+) ion and turns into the negatively charged compound p-nitrophenolate at medium pH.

Do copper ions activate tyrosinase enzyme? A biosensor model for the solution.

Some metal ions play a cofactor role for the activity of tyrosinase enzyme and one of them is copper ion. In this study an amperometric biosensor was developed in order to investigate the effect of the copper ions on the activity of tyrosinase enzyme. In the construction of the biosensor tyrosinase enzyme was immobilized on a Clark-type dissolved oxygen probe which was covered with a oxygen sensitive teflon membrane, by using a chemical covalent immobilization method based on gelatine and bifunctional reagent, glutaraldehyde.

An inhibition type amperometric biosensor based on tyrosinase enzyme for fluoride determination.

In this study, a new biosensor based on the inhibition of tyrosinase for the determination of fluoride is described. To construct the biosensor tyrosinase was immobilized by using gelatine and cross-linking agent glutaraldehyde on a Clark type dissolved oxygen (DO) probe covered with a teflon membrane which is sensitive for oxygen. The phosphate buffer (50mM, pH 7.

A novel biosensor based on activation effect of thiamine on the activity of pyruvate oxidase.

A biosensor based on pyruvate oxidase (POX) enzyme was developed for the investigation of the effect of thiamine (vitamin B(1)) molecule on the activity of the enzyme. The biosensor was prepared with a chemical covalent immobilization method on the dissolved oxygen (DO) probe by using gelatin and cross-linking agent, glutaraldehyde. POX catalyzes the degradation of pyruvate to acetylphosphate, CO(2) and H(2)O(2) in the presence of phosphate and oxygen.