Single-Walled Carbon Nanotube Optical Sensor Technologies

Single-walled carbon nanotube-based optical sensors offer the potential for quantitative detection in real-time with single-molecule sensitivity. Semiconducting carbon nanotubes emit photostable, near-infrared photoluminescence which is ultrasensitive to molecular adsorption and takes advantage of the ‘tissue transparent' spectral window. Sensor transduction involves several modalities including excitonic quenching as well as solvatochromic shifts. To translate analyte-binding events into a photoluminescence signal, polymer-encapsulated nanotube com¬plexes are formed via non-covalent assembly. The polymer confers selectivity to the sensor via two mechanisms: (1) sterically hindering adsorption to the nanotube surface, and (2) providing a molecular switch to modulate nanotube emission upon specific polymer-analyte interactions.