Molecule counting with alkanethiol and DNA immobilized on gold microplates for extended gate FET

► Molecule counting is very important for the biosensing chip which deserves to develop. ► FCV was employed for counting DNA molecules on Au microplates quantitatively. ► It was examined how the physical parameters of SAM changed with the carbon number. ► The molecule counting method with EGFET electronic detection was developed. ► The surface density of dsDNA was 1.36 molecules/100 nm2 on Au of EGFET.