Premium
Controlled Vectorial Electron Transfer and Photoelectrochemical Applications of Layered Relay/Photosensitizer‐Imprinted Au Nanoparticle Architectures on Electrodes
Author(s) -
Metzger Tzuriel S.,
TelVered Ran,
Willner Itamar
Publication year - 2016
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201503077
Subject(s) - photocurrent , photosensitizer , electron acceptor , electron transfer , electrode , photochemistry , electrochemistry , materials science , nanoparticle , acceptor , molecular imprinting , chemistry , redox , photoelectrochemistry , nanotechnology , inorganic chemistry , optoelectronics , selectivity , catalysis , organic chemistry , physics , condensed matter physics
Two configurations of molecularly imprinted bis‐aniline‐bridged Au nanoparticles (NPs) for the specific binding of the electron acceptor N,N ′‐dimethyl‐4,4′‐bipyridinium (MV 2+ ) and for the photosensitizer Zn(II)‐protoporphyrin IX (Zn(II)‐PP‐IX) are assembled on electrodes, and the photoelectrochemical features of the two configurations are discussed. Configuration I includes the MV 2+ ‐imprinted Au NPs matrix as a base layer, on which the Zn(II)‐PP‐IX‐imprinted Au NPs layer is deposited, while configuration II consists of a bilayer corresponding to the reversed imprinting order. Irradiation of the two electrodes in the presence of a benzoquinone/benzohydroquinone redox probe yields photocurrents of unique features: (i) Whereas configuration I yields an anodic photocurrent, the photocurrent generated by configuration II is cathodic. (ii) The photocurrents obtained upon irradiation of the imprinted electrodes are substantially higher as compared to the nonimprinted surfaces. The high photocurrents generated by the imprinted Au NPs‐modified electrodes are attributed to the effective loading of the imprinted matrices with the MV 2+ and Zn(II)‐PP‐IX units and to the effective charge separation proceeding in the systems. The directional anodic/cathodic photocurrents are rationalized in terms of vectorial electron transfer processes dictated by the imprinting order and by the redox potentials of the photosensitizer/electron acceptor units associated with the imprinted sites in the two configurations.