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Indexed by:期刊论文

Date of Publication:2014-06-17

Journal:ANALYTICAL CHEMISTRY

Included Journals:SCIE、EI、PubMed、Scopus

Volume:86

Issue:12

Page Number:5922-5928

ISSN No.:0003-2700

Abstract:A novel triphenylamine-based organic dye, TTA, with an acrylic group is designed to graft TiO2 nanoparticles for sensitive and selective photoelectrochemical sensing. The synthesized TTA possesses a high molar absorption coefficient, leading to an enhanced photoelectron emission ability of the electron donor. The carboxyl group of TTA acts as not only an electron acceptor but also a linker to connect TTA to TiO2 nanoparticles. Under irradiation, TTA shows fast intramolecular charge transfer from triphenylamine to carboxyl group via the pi-bridge of thiophene moiety, thus producing a sensitive photocurrent response. Meanwhile, the acrylic moiety provides an active site for the Michael addition reaction, which would destroy the pi-bridge and decrease the photocurrent response. Thus, a selective photoelectrochemical sensing strategy is proposed for detection of small biomolecules. Using cysteine as a model analyte, this sensing strategy shows a detectable range from 1 to 200 mu M, without the interference from natural amino acids and various biological reducing reagents. This work offers a new photoelectrochemical route to highly selective and sensitive detection of biologically important small molecules.