Fabrication of Integrated Dehydrogenase-Based Electrochemical Biosensors inorder to detection of amino acids in biological samples

One method to detect the Phenylketonuria (PKU) disease, is the using an enzyme electrochemicalbiosensors that they have to be more selectivity than other biosensors. In this biosensors, differentsubstrates are used for immobilization of enzymes and electrocatalytical structures[1]. This studydescribes a facile approach to the preparation of integrated dehydrogenase-based electrochemicalbiosensors through noncovalent attachment of an oxidized form of β-nicotinamide adeninedinucleotide (NAD+) onto graphene and graphene-based materials such as graphene oxide andgraphene quantum dots with the interaction between the adenine subunit in NAD+ molecules andgraphene nano-structures. With phenylalanine dehydrogenase (PDH) as a model dehydrogenasebasedrecognition unit, electrochemical studies reveal that phenylalanine is readily oxidized at thePDH/NAD+/GO-modified electrode without addition of NAD+ in the phosphate buffer. graphenebasedmaterials employed here not only serve as the electronic transducer and the support toconfine NAD+ cofactor onto the electrode surface, but also act as the electrocatalyst for NADHoxidation in the dehydrogenase-based electrochemical biosensors[2, 3]. Also, In this research, forthe first time, the carbon ceramic electrodes will be used that they are modified with carbonstructures as a substrate with high active surface to stabilize the enzyme of phenylalaninedehydrogenase and preparation of electrochemical biosensors phenylalanine amino acid withhigh stability and selectivity. At the PDH/NAD+/GO-based phenylalanine biosensor, the currentis linear with the concentration of phenylalanine being within a concentration range from 200 to500 mM. This study offers a facile and versatile approach to the development of integrateddehydrogenase-based electrochemical devices, such as electrochemical biosensors and biofuelcells.

Keywords:

Electrochemical biosensor , Graphene nano-structures , Phenylalanine , Carbonceramic