Electrical detection of hybridization and threading intercalation of deoxyribonucleic acid using carbon nanotube network field-effect transistors

Abstract

The authors study deoxyribonucleic acid (DNA) sensing characteristics of carbon nanotube network field-effect transistors (CNNFETs) by monitoring their electrical responses upon immobilization with a DNA probe, hybridization with DNA analytes, and intercalation with a $N,N^{\prime }$ -bis(3-propylimidazole)-1,4,5,8-naphthalene diimide modified with $\mathrm{Os}{(2,2^{\prime }\text{-}\text{bipyridine})}_2{\mathrm{Cl}}^{+}$ pendants. The CNNFETs immobilized by single-stranded DNA molecules demonstrate the selective sensing of its complementary and single-base mismatched DNA (difference of $\sim 16\%$ in reduction of normalized drain current $I_d$ ). Subsequent intercalation demonstrates a further sensitivity enhancement (difference of $\sim 13\%$ in $I_d$ reduction) due to specific binding between hybridized DNA and intercalators, corroborated by the x-ray photoelectron spectroscopy study.