[cassini.daniele's quote has been removed.]
Yes. This is what I was interested in. This is what I suspected.
Now how to measure this.... ???
I spoke with some Engineers about the lack of test instrumentation to take such measurements. One had an interesting idea on how to do this. I cannot remember the details, but we do keep in touch with him. Unfortunately, I made a career change and sid "goodbye" to biomed. -- long story --
The difficulty lied in the fact that the instrument must not interfere with the sample being measured. Being non-intrusive. I am unaware of existing instruments to do this at this time..
I still believe the measurement can be made and there is a lot to be learned from the outcome.
🙂And I still am interested in that field. Who knows, maybe one day I will switch back.
My belief is that if you excite the DNA with a specific electrical signature, there will be a resultant current signature. It is this resultant signature that interested me. Exciting the dna was one thing. How to measure such a small (pA) current is highly difficult. How to filter it out of all surrounding noise???
Have you looked at the work from Zwolak M & Di Ventra M. at California Institute of Technology, Pasadena?
They looked at the electronic signatures resulting from DNA strands. Fascinating..
🙂Also look at Lin X, Jiang X, Lu L. form University of Science and Technology of China
They have an article:
DNA deposition on carbon electrodes under controlled dc potentials.
ABSTRACT:
The native calf-thymus DNA molecule fully dispersed in solution was deposited onto highly oriented pyrolytic graphite, carbon fiber column and disk electrodes under controlled dc potentials. X-ray photoelectron spectroscopy, atomic force microscopy and electrochemical investigations indicated that network structures of DNA could be formed on various carbon electrode surfaces resulting in significant surface enlargement. The conformation, conductivity and stability of the deposited DNA layer largely depended on the concentration of the DNA deposition solution, the applied dc potential and the mode of electric field. The optimal condition for deposition of the DNA on carbon fiber disk electrode was determined as a deposition potential of 1.8 +/- 0.3 V versus 50 mM NaCl-Ag/AgCl and a deposition DNA solution of 0.1 mg ml(-1). Under this condition, the DNA was covalently bonded on the electrode surface forming a three-dimensional modified layer, generating a 500-fold enlarged effective electrode surface area and similarly enlarged current sensitivity for redox species, such as Co(phen)3(3+). A possible mechanism for the formation of DNA networks is proposed.
Message Edited by Support on 05-16-2005 08:36 AM
