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论文类型：期刊论文

发表时间：2014-06-17

发表刊物：ANALYTICAL CHEMISTRY

收录刊物：SCIE、EI、PubMed、Scopus

卷号：86

期号：12

页面范围：5922-5928

ISSN号：0003-2700

摘要：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.