Glucose biosensors based on organic light-emitting devices structurally integrated with a luminescent sensing element

A platform for photoluminescence $\left(\mathrm{PL}\right)$ based biosensing is demonstrated for glucose. The sensor is structurally integrated, i.e., individually addressable organic light-emitting device $\left(\mathrm{OLED}\right)$ pixels (serving as the light source) and the sensing element are fabricated on glass or plastic substrates attached back-to-back. This results in a very compact, potentially miniaturizable sensor, which should strongly impact $\mathrm{PL}$ -based biosensor technology. The sensing element is an oxygen-sensitive dye coembedded with glucose oxidase in a thin film or dissolved in solution. The glucose biosensor is demonstrated for two $\mathrm{OLED}$ ∕dye pairs: [blue $\mathrm{OLED}$ ]∕[$\mathrm{Ru}$ dye] and [green $\mathrm{OLED}$ ]∕[$\mathrm{Pt}$ dye]. Both $\mathrm{PL}$ -intensity and $\mathrm{PL}$ -lifetime modes are demonstrated for each pair; the lifetime mode eliminates the need for frequent sensor calibration. The sensor performance is evaluated in terms of design, dynamic range, limit of detection, and stability. The use of the glucose biosensor in conjunction with an oxygen sensor is also discussed.