Nevertheless, conventional mass spectrometry has limits. The technique is slow, bulky and expensive. Further, elaborate sample preparation is involved and the method is not capable of providing real-time information about molecular binding affinity. Affinity information is often critical for understanding biological activities such as antigen-antibody and drug-target interactions as well as a variety of molecular functions.
The new approach provides a simple, fast and miniaturized means of conducting molecular mass measurements. Unlike conventional mass spectrometry, Tao's approach aims at detecting the binding of molecules in their native environment, including under aqueous conditions, allowing not only mass measurement but also functional analysis. (more)
The mechanical oscillators are self-assembled on a chip surface. This bottom-up approach permits rapid, accurate fabrication of these tiny structures, measuring just a few nanometers in size. The method also permits precise control over the oscillators' resonant frequencies, at the same time allowing simple detection of the oscillations with high throughput.
Tao's technique makes use of two quantities, known in advance with precision: each oscillator's mass and the spring constanta measure of the connecting molecule's elasticity. The mass and spring constant of the oscillators are precisely defined, but they also can be tuned. This enables the resonant frequency of the oscillator to be adjusted from gigahertz to terahertz frequencies.
This frequency range is important, because it spans a region of the electromagnetic spectrum falling between infrared and microwave. As Tao notes, such frequencies are too low for conventional optical measurements and too high for typical electronic detections. To overcome these detection limits, the group will use specialized techniques.
A property known as surface plasmon resonance will be used for optical detection of the mol
|Contact: Joseph Caspermeyer|
Arizona State University