The development of biosensors to identify the molecular markers of specific genes is fundamental for the implementation of new techniques that allow the detection of specific DNA sequences in a fast, economic, and simple way. Electrical Bioimpedance Spectroscopy (EBiS) has been used for the diagnosis and monitoring of human pathologies, and is recognized as a safe, fast, reusable, easy, and inexpensive technique. This study proves the development of a complementary DNA (cDNA) biosensor based on measurements of EBiS and of the immobilization of DNA without chemical modifications, and presents the evaluation of its potential usefulness in the detection of the gene expression of an inflammation characteristic biomarker, NLRP3, is presented. The obtained results demonstrate that EBiS can be used to identify different gene expression patterns, and measurements were compared with Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) and validated by Quantitative Polymerase Chain Reaction (qPCR). These results indicate the technical feasibility of a biosensor of specific genes through bioimpedance measurements in the immobilization of cDNA.