Integrated Fluorescence Sensing
The excitation light must be blocked from reaching the sensor, but the fluorescence must be allowed through. We are developing patternable thin film filters to coat the sensors. This work is being done by Marc Dandin. The approach is based on incorporating light-absorbing molecules into a polymer matrix – in the case of UV-excitable fluorophores, we include a compound found in sunscreen, benzotriazole (BTA). Polymer matrices include PDMS, 1B31, and SU8. The performance, in terms of UV-rejection, is better than that achieved with thin-film interference filters.
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