Ultrasensitive Detection of Oligonucleotides: Single-Walled Carbon Nanotube Transistor Assembled by DNA Block Copolymer

Biosensors, which harness the unique specific binding properties of biomaterials such as proteis, are increasingly recognized as a powerful tool for chemical sensing. In this context, the detection of nucleic acids DNA and RNA will take on ever more importance for screening as the fields of genomics and diagnostics advance. The same properties that allow molecular recognition–strong, specific non-covalent interactions–also enable bottom-up assembly of sensing architectures. Here, we take advantage of such interactions for the self-assembly of field-effect transistors from semiconducting single-walled carbon nanotubes selectively dispersed by DNA-block-copolymers and anchored to the electrodes through DNA hybridization. These transistors can sensitively detect the hybridization of complementary target DNA strands through transduction of the chemical recognition event into electrical doping, achieving an analyte sensitivity of 10 fM. Such ultra-sensitive electrical-based detection removes the need for DNA amplification and offers a new route to nucleic acids diagnostics.