Facile and Rapid Visualization of Colorless Endocrine Disruptor Bisphenol A by Interfacial Charge-Transfer Transitions with TiO2 Nanoparticles

摘要

Bisphenol A (BPA) is an estrogen-mimicking endocrine disruptor, which has been widely used in the production of polycarbonates and epoxy resins. Because BPA is a colorless material owing to the wide HOMO-LUMO gap of ca. 4.3 eV, we cannot discern toxic BPA dissolved in solution with eyes. Here, we report a facile and rapid method for visible-light sensing of BPA with TiO2 nanoparticles. The chemical adsorption of BPA on anatase TiO2 nanoparticles via the two phenol groups induces interfacial charge-transfer (ICT) transitions from BPA to TiO2 in the visible region. The ICT transitions give rise to visible-light absorption up to ca. 600 nm, allowing visible-light sensing of BPA. This method is also applicable to other phenol-containing endocrine disruptors. More generally, to our best knowledge, this is the first demonstration for visible-light sensing of colorless toxic organic compounds based on ICT transitions.