We present two designs of organic optoelectronics for compact lab-on-chip fluorescence detection. In the first configuration, organic light emitting diode (OLED) and organic photo diode (OPD) are fabricated

Spatially programmable surface properties are important building blocks for future microfluidic and biosensor devices. We demonstrate switching of a photochromic surface with a blue organic light-emitting diode (OLED) suitable as an integrated on-chip light source. The surface of a positive polydimethylsiloxane (PDMS) replica of a fresh lotus leaf is covalently functionalized with a photoswitchable azobenzene selfassembled monolayer (SAM) employing "click chemistry." 80 % of the azobenzene molecules are switched from cis to trans state within 4 min of OLED irradiation. A spatially resolved study of the azobenzene switching properties on the naturally inhomogeneous lotus surface is conducted evaluating the transmission of a 355 nm laser beam. In the area of the leaf veins the highest change in the relative transmission of 100 % is obtained upon switching from trans form to cis form under UV illumination. In comparison, an azobenzene-functionalized flat glass surface exhibits only a 0.5 % change in the relative transmission.