Figure 5.

(A) Fluorescence response (F-F₀/F₀) for spectra of CB13 DNA-SWNTs upon addition of 100 μM DOX. Changing the ratio of SWNT:DNA (w/w) alters both the fluorescence emission intensity and response to DOX. 1 mL samples of 100 μM DNA suspending (i) 1 mg (red), (ii) 3 mg (yellow), or (iii) 5 mg (blue) SWNT. Each spectrum represents the average of 3 technical replicate measurements. (B) Fluorescence emission spectra of CB13-DNA SWNT before addition of (t=0), and after 10 min incubation with (t=10 min) 100 μM DOX. Time series traces of the (C) (6,5) and (D) (7,6) peaks reveal that the peak wavelength (red) shifts continuously over 10 min while the peak intensity (black) for (6,5) plateaus rapidly compared to (7,6). (E, F) Fluorescence response of normalized intensity (E) and wavelength (F) for the (7,6) chirality peak of CB13-DNA-SWNT versus DOX concentration. Triangles (red) and circles (black) represent separate experimental replicates. Each point is the average of 3 technical replicates with standard deviation as error bars. Curve fits were calculated using non-linear least squares. (G) Fluorescence emission spectra of CB13-DNA-SWNT in the presence of 0.1 mM of the anthracyclines doxorubicin (DOX), epirubicin (EPR) and daunorubicin (DAR). (H) Fraction of pristine SWNT (solid lines) and anthracycline-bound SWNT (dotted lines) calculated from fluorescence emission spectra as a function of concentration for the different anthracyclines. (I) Comparison of the fluorescence response of CB13-DNA-SWNT nanosensor to the chemotherapeutics doxorubicin (DOX) and dacarbazine (DTIC) at 0.1 mM concentration.