Functionalized InN ISFET for DNA Hybridization Detection

Ultrathin (10 nm) InN ion sensitive field effect transistors (ISFETs) with gate region modified with 3-mercaptopropyltrimethoxysilane (MPTMS) by molecular vapor deposition (MVD) are used to detect hybridization of deoxyribonucleic acid (DNA). The ultrathin InN ISFETs have a high sensitivity and short response time for anion detection, showing a great potential for chemical and biological sensing applications. A drain-source current decrease(~6 uA) was observed due to the attachment of negatively charged DNA. For a 12-mer oligonucleotide probe, the detection of 1 nM target DNA was accomplished, while the noncomplementary DNA with one base mismatch did not show any obvious current variation.