Figure 21.

Ratiometric sensing. a) NIR fluorescence of (GT)₁₅‐(7,6)‐SWCNTs in response to H₂O₂ compared to the nearly invariant (AT)₁₅‐(6,5)‐SWCNT reference at different time points. Reprinted from Ref. [20] with permission. b,c) Ratiometric sensing of dopamine and H₂O₂ using PEG‐PL as a reference and (GT)₄₀‐SWCNTs or SWCNTs functionalized with the hemin‐binding aptamer (HeApta). The reference sensor can be made from different colors of SWCNTs ((6,5) or (7,6) chirality). Adapted from Ref. [49] with permission. Copyright 2021 American Chemical Society.