Achieving Enzyme Stability Using a Simple Fabrication Procedure: The Alcohol Dehydrogenase Example

The use of screen-printing biosensors has been updated in this article as a tool to analyze the electron transfer process involving redox proteins or enzymes. The aim of this research was to fabricate a simple apparatus which allowed the use of the enzymes (in the solid state) to maintain their stability. To prove this concept an enzyme in the solid state was mixed with the carbon ink and this mixture was used to print the working electrode. We choose as proving the alcohol dehydrogenase. The first reason is because it metabolizes the alcohol, which can be present in biological samples of blood, saliva and urine and also in the beverage; the second is that this enzyme is still a challenge to electrochemistry due to having lower stability in sensors. The results show that in this device the enzyme was active and stable during all the experiments and in the experimental conditions that could catalyze the ethanol to acetaldehyde. These devices have the advantage of being disposable, cheap and are easy to fabricate. And also, they do not need expensive tools to be fabricated, they only need 2 μL of electrolyte or sample, and they need lower amounts of enzyme to permit electrochemical studies.