A new photoelectrochemical chiral sensor was developed in this study, which was achieved through the combination of Langmuir-Blodgett and self-assembly techniques to cast a monolayer of chiral metal complex A-[Os(phen)(3)](2+) onto a single layer TiO2 film on an indium tin oxide (ITO) substrate. When being applied for photoelectrochemical sensing of binaphthol isomers, the as-prepared hybrid film exhibited a much higher chiral selectivity than the ITO/clay/A-[Os(phen)(3)](2+) film reported earlier. The experimental detection limit is about 20 pm. The great enhancement is because TiO2 provides a better charge separation, which facilitates the electron transfer reaction of those excited Os(II)(+). For small peptide derivatives of 5-fluorouracil, the ITO/TiO2/A-[Os(Phen)(3)](2+). film yielded a chiral selectivity of 1.5. (C) 2012 Elsevier B.V. All rights reserved.