Fabrication of Enzymatic Electrochemical Biosensors for Real-Time Nicotine Detection

Biosensors provide an output signal based upon a successful recognition of an analyte. Key to this process in oxidase-based biosensor is analyte recognition by an enzyme and subsequent signal transduction. As such, the sensor design process must successfully address a series of requirements associated with the interface between the enzyme and an electrode. Here we present the development, assessment, and optimization of a nicotine sensor based on a nicotine catabolizing redox enzyme and Prussian Blue coated screen-printed electrodes to afford a chronoamperometric response proportional to nicotine. An optimized polymeric matrix immobilization method maintains enzymatic activity on the mediator-coated screen-printed electrode and enables quantitative detection of nicotine. The resulting biosensor detects nicotine in urine with high sensitivity with a limit of detection of 34 μM over the range of 0-200 μM.