Highly sensitive Electrochemical BioMEMS for TNF-alpha detection in human saliva: Heart Failure

Prediction of disease progression using saliva as a diagnostic medium has roused the interest of scientific researchers in the 10 last past years. Potentially important biomarkers are increased in saliva during local and systemic inflammation. In the present study we have developed a highly sensitive biosensor for TNF-alpha detection in human saliva of patients suffering from heart failure. Therefore, a fully integrated electrochemical BioMEMS was developed in order to increase the sensitivity of detection, decrease the time of analysis, and to simultaneously detect varying cytokine biomarkers using eight gold working microelectrodes (WE). The monoclonal antibodies (mAb) anti-human Tumor Necrosis Factor alpha (anti-TNF-alpha) were immobilized onto gold icroelectrodes through functionalization with carboxyl diazonium. Cyclic voltammetry (CV) was applied during the microelectrode functionalization process to characterize the gold microelectrode surface properties. Finally, electrochemical impedance spectroscopy (EIS) characterized the modified gold microelectrodes, and the detection range of TNF-alpha cytokines was from 1pg/mL to 15 pg/mL.