Detecting single-nucleotide polymorphisms (SNPs), which are associated with a variety of diseases, necessitates the development of label-free electronic biosensors for point-of-care applications that can be straightforwardly used in clinical settings. We have designed and fabricated biosensors using ultrathin-film indium oxide field-effect transistors (FETs) that differentiate hybridization of target oligonucleotide sequences with high sensitivity and selectivity. The semiconducting channels of the FETs are chemically functionalized with single-stranded DNA probes to test selectivity towards complementary target sequences <i>versus</i> target sequences that contain SNPs. Hybridization of negatively charged DNA results in significant changes in current responses enabling sensing of DNA hybridization with femtomolar detection limits. By taking advantage of differences in stabilities and conformations of sequences with different base pair mismatches, we demonstrate the ability of DNA-functionalized FETs to distinguish hybridization between fully complementary DNA sequences, and analogous sequences with different types and locations of SNPs. The development and implementation of biosensors that can sense and differentiate oligonucleotide sequences with SNPs at very low concentrations presents new opportunities in the fields of disease diagnostics and precision medicine.

Single-nucleotide polymorphism detection <i>via </i>ultrathin-film field-effect transistors

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Single-nucleotide polymorphism detection via ultrathin-film field-effect transistors