Total Internal Reflection-Based Biochip

Total internal reflection fluorescence microscopy (TIRFM), also known as evanescent wave microscopy, has received considerable recognition in recent years due to its unique capabilities. TIRFM enables the study of surface molecular dynamics at the single molecule level through the generation of a thin evanescent wave at a glass/liquid interface by total internal reflection (TIR). TIRM has been successfully utilized in detecting real time DNA surface attachment and hybridisation and recording molecular motors activity.

Our effort is focused on designing a TIR-based biochip platform (figure 1) that simplifies current TIR configurations and fabrication processes while providing flexibility for the future development of an integrated miniaturized optical system.The biochip consists of a polymer-filled cavity for efficient light coupling. One of the reflective sidewalls of the cavity act as a micromirror that directs the excitation light at a predefined angle. Microfluidic channels are also integrated on top of the chip for sample delivery.

References:

1. Chronis N. and Lee L.P., "Total Internal Reflection-based Biochip Utilizing a Polymer-filled Cavity with a Micromirror Sidewall," Lab on a Chip, 4 (2), 125-130 (2004).
2. Chronis, N. and Lee L.P. "Total Internal Reflection-based Biochip for High Throughput Bioassays", Seventh International Conference on Micro Total Analysis Systems (µTAS), Squaw Valley, California, 5-9 October 2003, p.1323-6.

(A) The TIR-based biochip with integrated microfluidic channels forming a Y configuration (where the channels cross). The backside of the chip is shown in the inset. (B) Schematic cross section of the TIR region. The micromirror redirects the excitation light to the glass-liquid interface.