MicroRNAs and other small oligonucleotides in biofluids are promising biomarkers, but conventional assays require complex processing steps unsuitable for point-of-care assays or implantable/wearable sensors. Single-walled carbon nanotubes are an ideal material for implantable sensors due to emission in the near-infrared spectral region, photostability, and exquisite sensitivity. We engineered a carbon nanotube-based platform capable of real-time optical quantification of hybridization events of microRNA and other oligonucleotides for use in vivo. The sensor mechanism derived from competitive effects between displacement of both oligonucleotide charge groups and water from the nanotube surface, resulting in a solvatochromism-like response. The platform allowed detection via single molecule sensor elements and multiplexing using multiple nanotube species. The sensor monitored toehold-based strand displacement events, reversing the sensor response and regenerating the sensor complex. The sensor functioned in whole urine and serum, and it non-invasively measured DNA and microRNA biomarkers after implantation into live mice.

Citation Format: Daniel A. Heller, Jackson D. Harvey, Prakrit V. Jena, Ryan M. Williams, Thomas V. Galassi, Hanan A. Baker, Daniel Roxbury, Gül Zerze, Jeetain Mittal. A nanoscale optical reporter implant for miRNA biomarkers in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-222. doi:10.1158/1538-7445.AM2017-LB-222