Voltammetric techniques provide a general and sensitive approach for direct or multistep measurement for biomarker detection in lung cancer. These methods provide the possibility of simultaneous measurement of various analytes in a short period of time. CV (cyclic voltammetry) is becoming an important tool in many areas of chemistry and biochemistry. It is widely used for the study of redox processes and for understanding reaction intermediates. In this technique, potential is varied over a fixed range in a forward and backward direction and current is monitored. In DPV (differential pulse voltammetry), potential with a series of fixed amplitude pulses is scanned between initial and final potential. In the simplest voltammetric technique, LSV (linear sweep voltammetry), potential is applied to a working electrode and scanned linearly over the range, and the current is measured. Tang and co-researchers proposed the electropolymerized poly o-aminophenol/Au with AuNP modified anti-CEA onto an Au surface-based biosensor for CEA estimation via label-free EIS technique.