title: Gold Nanorod Enhanced Fluorescence Enables Single-Molecule Electrochemistry of Methylene Blue.
abstract: Redox reactions are central to energy conversion and life metabolism. Herein we present electrochemical measurements with fluorescent readout of the redox-sensitive dye Methylene Blue (MB), at the single-molecule (SM) level. To overcome the low fluorescence quantum yield of MB we enhanced fluorescence by using individual gold nanorods to achieve the required sensitivity. By measuring the same molecule at different electrochemical potentials we determined the mid-point potential of each single molecule through its redox-induced fluorescence blinking dynamics.
authors.affiliation: Huygens-Kamerlingh Onnes Laboratory, Leiden University, 2300, RA, Leiden, The Netherlands.
authors.forename: Weichun
authors.identifier: 0000-0002-7286-7661
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Huygens-Kamerlingh Onnes Laboratory, Leiden University, 2300, RA, Leiden, The Netherlands.
authors.forename: Martín
authors.identifier: 0000-0001-8086-2580
authors.initials: M
authors.lastname: Caldarola
authors.affiliation: Huygens-Kamerlingh Onnes Laboratory, Leiden University, 2300, RA, Leiden, The Netherlands.
authors.forename: Biswajit
authors.identifier: 0000-0002-6101-8728
authors.initials: B
authors.lastname: Pradhan
authors.affiliation: Huygens-Kamerlingh Onnes Laboratory, Leiden University, 2300, RA, Leiden, The Netherlands.
authors.forename: Michel
authors.identifier: 0000-0002-3607-3426
authors.initials: M
authors.lastname: Orrit
keywords: electrochemistry; enhanced fluorescence; gold nanorods; methylene blue; single-molecule studies