BioMEMS

In a biological cell, enzyme systems play an important role since they direct the metabolism of the cell by controlling all processes to occur at a specific rate. One of the important research fields in cell biology is to investigate the structure and function of complex enzyme systems. However, the dynamic activities of enzymes in a living cell are hard to record. In this project, we probe NADH-Cytochrome b5 Reductase enzyme activity in a living cell by quantized plasmon quenching dips nanospectroscopy, a technology we developed earlier to detect the type of molecules conjugated on...

The project aims to develop an integration method for CMOS chip and microfluidics, specifically for immunosensing system with microfluidic system for sample preparation and CMOS magnetic sensor for detection. Solving the size mismatch between CMOS chip (typically mm scale) and microfluidics (cm scale) while maintaining the functionality and interconnect metallization of CMOS, as well as seamlessly delivery the fluid to the sensor surface on the CMOS chip through microfluidics are the key considerations for the integration. On the other hand, the integrated biosensor will be a...

We develop a technique for producing synthetic microbial patterns by means of direct activation and inactivation of gene expression in an initially homogenous population of cells using a microfluidic chemical interface system. A strain of E. coli was engineered such that the presence of the membrane diffusible molecule acyl-homoserine lactone (AHL) activates the production of more AHL, thereby creating a positive feedback loop. Since the half-life of AHL decreases in high pH solutions, this feedback loop can be inhibited in a specific area by modulating the local pH using a...

This project aims to develop a magnetic scanning probe microscope based on a magnetic tunnel junction (MTJ) sensor for the detection of magnetically-labeled biomolecules. Paramagnetic particles are employed as markers and incorporated with commercial DNA microarray technology to produce magnetically labeled DNA microarrays. An external magnetic tunnel junction is mechanically scanned across these arrays to detect and map out the localized magnetic fields from these particles. This new approach offers the potential to image centimeter-scale arrays of thousands of DNA spots while still...