Salivary cortisol analysis using metalloporphyrins and multi-walled carbon nanotubes nanocomposite functionalized electrodes

Continuous monitoring of biomarkers in physiological fluids, such as blood, sweat or saliva, by means of lowcost and non-invasive devices, is of crucial importance to improve diagnosis and disease treatment. Herein, an electrochemical sensor fabricated using screen printed carbon electrodes (SPCE) have been investigated as a lowcost sensor platform for monitoring cortisol levels. The detection mechanism of the proposed sensor is based on electrochemical reduction of cortisol by metalloporphyrin (MTPP) at the multi-walled carbon nanotubes (MWCNTs) modified electrodes. Computational modelling studies and binding energy calculations have been performed to select a suitable MTPP for cortisol detection. The proposed screen printed cortisol sensor was used to accurately detect variations in salivary cortisol levels in young adult women. To validate the accuracy of the sensor, the results of salivary cortisol levels obtained with the sensors are compared with the commercial ELISA and found to be correlated.