title: A Ratiometric Sensor Using Single Chirality Near-Infrared Fluorescent Carbon Nanotubes: Application to In Vivo Monitoring.
abstract: Advances in the separation and functionalization of single walled carbon nanotubes (SWCNT) by their electronic type have enabled the development of ratiometric fluorescent SWCNT sensors for the first time. Herein, single chirality SWCNT are independently functionalized to recognize either nitric oxide (NO), hydrogen peroxide (H(2)O(2)), or no analyte (remaining invariant) to create optical sensor responses from the ratio of distinct emission peaks. This ratiometric approach provides a measure of analyte concentration, invariant to the absolute intensity emitted from the sensors and hence, more stable to external noise and detection geometry. Two distinct ratiometric sensors are demonstrated: one version for H(2)O(2), the other for NO, each using 7,6 emission, and each containing an invariant 6,5 emission wavelength. To functionalize these sensors from SWCNT isolated from the gel separation technique, a method for rapid and efficient coating exchange of single chirality sodium dodecyl sulfate-SWCNT is introduced. As a proof of concept, spatial and temporal patterns of the ratio sensor response to H(2)O(2) and, separately, NO, are monitored in leaves of living plants in real time. This ratiometric optical sensing platform can enable the detection of trace analytes in complex environments such as strongly scattering media and biological tissues.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors.forename: Juan P
authors.initials: JP
authors.lastname: Giraldo
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors.forename: Markita P
authors.initials: MP
authors.lastname: Landry
authors.forename: Seon-Yeong
authors.initials: SY
authors.lastname: Kwak
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors.forename: Rishabh M
authors.initials: RM
authors.lastname: Jain
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors.forename: Min Hao
authors.initials: MH
authors.lastname: Wong
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Iverson
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors.forename: Micha
authors.initials: M
authors.lastname: Ben-Naim
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Strano
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D005453:Fluorescence; D005609:Free Radicals / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007259:Infrared Rays; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009569:Nitric Oxide / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects; D013010:Sonication; D013535:Suspensions; D013997:Time Factors
chemical_list: D005609:Free Radicals; D037742:Nanotubes, Carbon; D013535:Suspensions; D009569:Nitric Oxide; D006861:Hydrogen Peroxide
keywords: free radicals; optical nanosensors; reactive oxygen species; sensors, plant nanobionics