Fig. 1. (a) Schematic diagram of interdigital electrode；(b) Experimental device of biosensor system.

Fig. 2. Lithographic grid image (LC cell）. (a) LC pool； (b) LC pool containing BSA.

Fig. 3. Schematic diagram of liquid crystal molecular orientation and polarization direction of outgoing light. (a) No voltage is applied； (b) Voltage is added (without BSA）； (c) Voltage is high enough； (d) Voltage and BSA is added at the same time.

Fig. 4. Optical images of LC photopolymer composite film at different voltage when BSA concentration is 10^-3 g/mL. (a) 0 V； (b) 10 V； (c) 20 V； (d) 30 V； (e)40 V； (f)50 V.

Fig. 5. POM images with various applied voltage. (a) 10^-3 g/mL； (b) 10^-4 g/mL； (c) 10^-5 g/mL； (d) 10^-6 g/mL； (e)10^-7 g/mL (top row 0 V，bottom row 15 V）.

Fig. 6. Mean gray value of BSA with different concentrations changed with voltage.

Fig. 7. (a) Relationship between BSA concentration and image gray level when voltage is 0 V and 5 V； (b) Calibration curve.

Fig. 8. Optical images of liquid crystal photoinduced polymer composite films at (a) different concentrations of BSA and (b) different voltages (0，5，20，50 V）.

Fig. 9. Gray values of images between electrodes in the liquid crystal cell at different voltages