Conversion of absorption to fluorescence probe in solid-state sensor for nitric oxide and nitrite

A hydrogel bi-layer structure is used to convert an absorption type to a more convenient fluorescent type probe film for aqueous nitric oxide (NO) and nitrite (NO2-). In the bottom layer the commercial probe molecule 1,2-diaminoanthraquinone (DAQ) is dispersed in poly 2-hydroxyethyl methacrylate (poly HEMA), in the top layer the red inorganic phosphor is dispersed in poly HEMA. Both optical excitation and detection is from the bottom. This bi-layer is integrated with organic light-emitting diode (OLED) and organic photo-detector to form a real-time solid-state sensor. The sensor is responsive to NO bubbling, and remains stable in acid condition.

The bi-layer structure to convert the absorbance modulation of DAQ into the fluorescence signal of the R670 phosphor is shown.Figure optionsDownload as PowerPoint slideHighlights
► We convert an absorption type to a more convenient fluorescent type probe film.
► We realized a real-time solid-state sensor specific to nitric and nitrite.
► The limit of detection is 10−4 M.