Scientists have created a miniaturized phosphorescence sensor. It combines marker and sensor on a small chip surface about thumbnail size—a silicon chip houses both the OLED controller and the sensor front-end. Modulated blue OLED light excites the chemical marker. The marker’s phosphorescent response is then detected directly inside the sensor chip. The marker determines the substance to be measured.
The current sensor that excites the oxygen-sensitive marker emits blue light in a 4.7 by 2.2 mm area. After excitation, the decay time of the light emitted by the marker is a parameter of the oxygen concentration in the environment. The significantly lower phosphorescence signal is recorded using integrated silicon photodiodes, amplified locally in the chip, and then compared to the excitation signal in phase shift. The researchers hope to significantly reduce the chip size in the future, eventually achieving a total chip size of less than 2 by 2 mm.
According to the researchers, the sensor chip will serve as a platform for future developments, such as the measurement of additional parameters and deployment in other environmental conditions.
The researchers will improve the sensor system in the future to allow for multiparameter measurements. According to the researchers, the phosphorescence sensor could monitor and evaluate cell cultures in small, disposable culture vessels and bioreactors.