On-chip fluorescence detection using organic thin film devices for a disposable lab-on-a-chip

In this paper, we present a high-sensitivity approach for on-chip fluorescence-based measurements for disposable lab-on-a-chip (LOC) with an integrated organic light-emitting diode (OLED) excitation source and organic photodiode (OPD) detector. A simple and inexpensive crosspolarization scheme was used to filter out excitation light from the fluorescent dye emission spectrum. We incorporated a bilayer OPD detector with responsivity 10 times higher than conventional single heterojunction OPD, resulting in a detection limit of 1 nM, which is a 1,000-fold improvement over previous publications. The dynamic experiment was conducted and the result shows promising application in realtime fluorescence analysis. The demonstrated on-chip fluorescence detection approach is ideally suited for integration with disposable LOC devices for point-of-care diagnostics and on-site environmental testing.