(174n) Engineering Colloidal Templates for Tuning Nanoparticle Surface Interactions and Optical Responses

Due to their distinct and advantageous fluorescence properties, semiconducting single-walled carbon nanotubes (SWCNTs) are being applied to a variety of optical sensing applications. Limitations in solubility and biocompatibility have been overcome by non-covalently functionalizing the surface of the SWCNT with wrappings using techniques that retain its inherent fluorescence. Though wrappings based on surfactants and single-stranded DNA (ssDNA) have been extensively studied for this purpose, they are limited by factors such as lack of selectivity and lower fluorescence quantum yield, respectively.In this study, we take advantage of the higher fluorescence emission of surfactant-coated SWCNTs and focus on new approaches that can tune their selectivity as sensors. Through the concomitant monitoring of both the fluorescence intensity and wavelength position of emission peaks, we demonstrate the ability to increase the selectivity of sensors based on surfactant-suspended SWCNTs while retaining their higher fluorescence intensity. These results provide not only a promising avenue for rationally designing SWCNT sensors, but also insight on the mechanisms governing the selectivity of existing SWCNT-based optical sensors.