On-chip droplet enhanced fluorescence emission for low concentration protein measurement

On-chip droplet enhanced fluorescence emission for low concentration protein measurement is presented in this paper. The system includes T-junction of microchannel for micro-droplet generation and two integrated optical fibers for excitation laser input and fluorescence detection. The excitation light is confined in the droplet by total internal reflection to increase the optical path length, which enhances the fluorescence emission. The on-chip droplet features higher stability and easier manipulation. The size of the droplet can be varied by changing the flow conditions. The intensity of the droplet enhanced fluorescence emission is much higher than the intensity of the free space fluorescence, which promises wide applications in biological detection and measurement.