Preparation of ZnO Quantum Dots and Study on Its Interaction with Acridine Orange

ZnO quantum dots were prepared by homogeneous precipitation using anhydrous zinc chloride (as raw material) and sodium hydroxide (as precipitant) with stirring for 24 h at room temperature. Mechanism of interaction of ZnO QD′s with acridine orange (ADO) was studied by fluorophotometry and UVVis absorption spectroscopy. It was found that: ① a compound complex was formed by interaction of ZnO QD′s with ADO, based mainly on the van der Waal′s force and the action of hydrogen bond, and quite strong binding force between the 2 reactants was attained as shown by the high value of the binding constant; ② fluorescence quenching of ZnO QD′s at its λem of 349 nm due to its reaction with ADO was observed, which was proved to be a static process; ③ as calculated by the Forster′s FRET principle, distance between molecules of ADO and ZnO QD′s was found to be 1.98 nm (less than 7 nm), and its was deduced that intermolecular nonradiative energytransfer was occurred.