By Jezz Leckenby, Small Times guest contributor
Harvard Professor Charles Lieber
Mar. 6, 2007 — Attendees at Pittcon 2007 (the Pittsburgh Conference for Analytical Chemistry and Applied Spectroscopy) were inspired to think about nanotechnology. Micro and nanotechnologies constituted a theme in the conference and exhibits—and the plenary lecture featured Harvard Professor Charles Lieber, widely recognised as a leader in nanotechnology. Lieber’s work blends physics and chemistry with electrical and biological systems, and is focused on “bottom up” manufacture using components a few nanometers in size. He uses nanowires to construct devices and circuits, and chemical synthesis to encode information for detection of biomarkers, explosives, and more.
Lieber summarized his research by saying that he has studied nature’s building blocks to understand their fundamental properties and structure on the nanoscale. From these, he has developed new concepts that are enabling divergence from conventional paradigms. The resulting hybrid systems, created from the bottom up, have the potential to impact science, technology, and society at all levels. Moreover, they will undoubtedly open up new areas and capabilities that are simply unattainable today.
Lieber’s group has used a number of cancer markers to test the technology, and has used it to make the first measurements on blood serum. Applications are also being studied to assist with chemical threat detection at astonishing sensitivities: better than 0.1 parts per trillion!
Exciting work is now under way where an array of nanowires is first patterned with chemicals used to grow neurons. The nanowires are used to both excite and record changes of the axons which conduct electrical impulses away from the nerve cell body. The goal is to be able switch the neurons on and off.
While Lieber has been able to demonstrate multiplexed detection using nanowires arrays, there is a need for sophisticated electronics to process the signals—and not surprisingly, the scale-up process is in its infancy. However, progress indicates an ability to measure reactions on the nanoscale, and to enable single-molecule sensitivity.
Building the “ultimate sensor”—able to detect a single particle such as a virus—is one of Lieber’s goals. Early tests have shown the ability to detect Influenza A receptors through a drop in conductance.