三苯胺功能染料的合成及在谷胱甘肽超低电位光电检测中的应用

设计合成了一种具有D-π-A结构的三苯胺功能染料(TCA),并通过分子结构中的羧基将其配位于TiO_2纳米粒子修饰的光电极表面,发展了一种可在超低电位下高灵敏检测谷胱甘肽(GSH)的光电传感方法.该TCA分子以三苯胺为电子给体,噻吩为桥连基团,氰基乙酸为电子受体.在可见光的照射下,TCA通过分子内电子转移将光电子由三苯胺经噻吩和羧基注入到TiO_2的导带能级,进而注入基底光电极,产生阳极光电流;同时,TCA被氧化到氧化态.由于氧化态TCA的稳定性好,可循环被生理活性小分子GSH还原,并产生放大的阳极光电流.TCA功能化的TiO_2纳米粒子修饰电极对GSH表现出了极高的催化活性,在波长为480 nm的可见光照射下,在0 V的超低电位下即可实现对GSH的催化氧化.基于这一性质,发展了一种可用于GSH检测的光电传感方法.在最优条件下,该传感器对浓度为2~100μmol/L和0.1~2.4 mmol/L的GSH具有良好的线性响应,检出限低达1μmol/L.此外,该光电传感器具有较好的选择性,可排除13种氨基酸和生理活性物质多巴胺及氢醌的干扰,因此具有一定的实际应用前景.

Synthesis of Triphenylamine Functional Dye for Highly Sensitive and Ultra-low Potential Photoelectrochemical Sensing of Glutathione

A triphenylamine functional dye( TCA) was synthesized and integrated with TiO2 nanoparticles for the fabrication of photoelectrochemical( PEC) biosensors. The as-synthesized TCA with triphenylamine as an electron donor, thiophene as a π bridge and a carboxyl group as an electron acceptor possessed high molar absorption coefficient in visible light region, suitable excited state energy level and good excited state stability, as well as strong coordination ability with TiO2 nanoparticles. Taking advantages of these merits, the TCA is bounded on TiO2 nanoparticle and modified on the surface of fluorine doped tin oxide electrode ( TCA-TiO2/FTO) . The obtained TCA-TiO2/FTO electrode showed a photocurrent response at 0 V to a light excitation of 480 nm, which could be further enhanced through an oxidation process of biomolecules by the hole-injected TCA. Using gluthathione as a model analyte, a sensing strategy for sensitive PEC biosensing at an ultra-low potential and under irradiation of visible light was developed. Under optimal conditions, the PEC biosensor shows good linear relationships with GSH concentration in the ranges of 2 to 100 μmol/L and 0. 1 to 2. 4 mmol/L, with a detection limit of 1. 0 μmol/L. This PEC biosensing platform offers an alternative method for monitoring biomolecules and provides a new strategy to design PEC biosensors with organic dyes.