Reflection-fluorescence ratios probe for the stable detection of glucose

Herein, an optical ratios probe with reflection (RE) and fluorescence (FL), named as RE-FL ratios probe, has been developed for the ratiometric detection of glucose (GLU). This probe was prepared through self-assembling monodisperse colloids into opal photonic crystal and immobilizing fluorescence imidazolium ionic liquids as molecular recognition elements. So there was a periodic three-dimensional face-centered cubic arrayed structure and emissions of strong RE and FL in the probe, which allowed dual optical detection of the target analyte. From the results, it was learned that RE and FL emissions of RE-FL ratios probe were decreased when an increase of GLU concentration, and the resulting ratiometric optical changes can be quantitatively correlated to GLU concentration from 1 to 64 mM. The detection of probe was characterized by simple operation, stability, reusability and glucose oxidase independence. Furthermore, the probe successfully used to detect GLU in the real serum sample and showed great stability compared with the only FL pattern. Different types of appropriated recognition elements are expected to be introduced into opal photonic crystals to construct variety ratiometric optical probes in the wide of applications.