ZnO/MWCNTs/Au Based Nano Biosensor for Detection of Lactate in Food Samples

A lactate biosensor has been designed for the detection of lactate in a real sample. A combination of composite material comprising of multi-walled carbon nanotubes (MWCNTs) and zinc oxide nanoparticles has been used as working electrode, which were deposited on gold (Au) wire. This was treated as working electrode for the preparation of a LDH-based amperometric biosensor along with acetyl coenzyme, which acts as the mediator to enhance electron transportation. The biosensor showed excellent results in terms of stability, response time, and sensitivity. The sensitivity of the biosensor is 4.487 mA/µM and its linearity is between 10 µM and 100 µM. The biosensor has a 0.67 µM limit of detection with a response time of 8 sec. The optimal temperature is 35°C, and the optimal pH is 8. All the results confirmed that the ZnO/MWCNTs/Au electrode, along with acetyl coenzyme, acts as a suitable matrix for the purpose of immobilizing LDH enzymes for the formation of lactate biosensors.