Detection of KRAS mutation by combination of polymerase chain reaction (PCR) and EIS sensor with new amino group functionalization

Abstract A capacitive electrolyte–insulator–semiconductor structure was introduced to quantify and distinguish point mutation from the corresponding PCR product of KRAS gene. Si 3 N 4 surface with remote NH 3 plasma is proposed to form amino group for DNA probe immobilization. The sensing response was investigated by capacitance–voltage measurement. A linear relationship was found between the reference voltage and DNA concentration from 10 −6 to 10 −9  M. Non-complementary DNA was used for specificity testing, no DNA hybridized with DNA probes and the specificity of EIS structure with NH 3 treatment was confirmed. Compared with APTES silanization and NH 3 plasma treatment, the sample with NH 3 plasma treatment reveal excellent selectivity and specificity, even in the presence of non-complementary DNA. The NH 3 plasma treatment provided suitable method which compatible CMOS technology and could be improved accuracy of bio-sensing in clinical diagnosis.