Semiconducting Single-Walled Carbon Nanotubes (SWCNTs) have a unique combination of optical, chemical, and physical properties that render them suitable for a broad range of applications^1–3.  Since SWCNTs are composed exclusively of surface atoms, the fluorescence emission of the nanotubes is very sensitive to the surrounding environment, enabling single-molecule detection limits that are especially desirable for biosensing applications. The selectivity of SWCNT-based fluorescence sensors can be tuned by engineering a polymer wrapping that covers the nanotube surface, imparting the nanotube with molecular recognition capabilities.  The challenge in creating these near-infrared (NIR) fluorescence sensors lies with tuning the specificity of the sensor by altering the wrapping properties. Though the exact mechanism by which polymers render surface selectivity is an area of active area of research⁴, researchers have been nonetheless able to engineer wrappings by screening an assortment of SWCNTs wrapped in various polymers and monitoring fluorescence changes in response to different analytes.

In contrast to this empirical approach, we have developed ”smart” wrappings capable of pre-defined molecular recognition towards a specific analyte of interest. By applying established synthetic and biological techniques for engineering specificity, our platform provides an interdisciplinary approach towards exploring the underlying molecular mechanism and versatility in tuning optical SWCNT-based sensors. The results of this work provide a seminal proof-of-concept approach in developing smart sensing technologies.

References

(1)      Han, C.; Doepke, A.; Cho, W.; Likodimos, V.; De La Cruz, A. a.; Back, T.; Heineman, W. R.; Halsall, H. B.; Shanov, V. N.; Schulz, M. J.; Falaras, P.; Dionysiou, D. D. Adv. Funct. Mater. 2013, 23(14), 1807–1816.

(2)      Choi, Y.-E.; Kwak, J.-W.; Park, J. W. Sensors 2010, 10(1), 428–455.

(3)      Liu, Z.; Chen, K.; Davis, C.; Sherlock, S.; Cao, Q.; Chen, X.; Dai, H. Cancer Res. 2008, 68(16), 6652–6660.

(4)      Z. W. Ulissi, J. Zhang, V. Sresht, D. Blankschtein, M. S. Strano,  Langmuir 2015, 31(1), 628–636.