Cyclic voltammetry (CV) may be used with novel sensors for identifying the presence of target sequences complementary to probe sequences. The sensor may include an electrode layer (which is used as a working electrode in a CV system), a conductive polymer layer, and probes immobilized (e.g., via sulfur) on the conductive polymer layer. The conductive polymer layer may be polyaniline, or the like. The probes may be immobilized on the polymer layer using an electro-chemical immobilization technique in the presence of nucleophiles, such as thiol groups for example. The probes may be oligionucleotides. Thus, the sensors may be used for identifying genomic sequence variations and detecting mismatch base pairs, such as single nucleotide polymorphisms (SNPs) for example.