Controlling The Optical Properties of Near-Infrared Nanotube Sensors through Bioengineering

Single-walled carbon nanotubes (SWCNTs) emit fluorescence that is ideal for a breadth of optical sensing applications. The near-infrared emissions are minimally absorbed by biological tissue, biofluids, and other visibly opaque materials. This property motivates their use for packaging and deep-tissue applications. The indefinite photostabilities and optical sensitivity to changes in their environment further justify the use of SWCNTs for continuous optical monitoring. However, SWCNTs require surface functionalizations to control the selectivity of their interactions and the specificity of the resulting sensors.<br/>Biomolecules like proteins and DNA show unparalleled molecular specificity towards various bioanalytes. Although they are commonly functionalized onto various surfaces to control the specificity of these surfaces towards analytes, their interactions with the surfaces themselves are often suboptimal. In the case of SWCNTs, these sub-optimal interactions limit sensor performance and response. This presentation highlights recent advancements that rely on bioengineering strategies, including directed evolution, mutagenesis, and xeno nucleic acids, for tuning the performances of bio-based optical SWCNT sensors.