Nanocrystalline quantum dots (QDs) are a new class of modern f luorophore, and they provide many interesting approaches to the development of fluorescence sensors. QDs have unique optical and electronic properties distinct from the bulk material, such as a sizedependent bandgap energy, broad excitation spectra, narrow symmetric and tunable emission spectra [17]. Furthermore, QDs exhibit better optical characteristics than the classical organic f luorophores, including large fluorescence quantum yields, high photobleaching thresholds, and excellent photostability [17,18]. However, the use of QDs for the detection of pho