Navigation Links
Femtogram-level chemical measurements now possible, U. of I. team reports
Date:3/27/2008

CHAMPAIGN, Ill. Finding a simple and convenient technique that combines nanoscale structural measurements and chemical identification has been an elusive goal. With current analytical instruments, spatial resolution is too low, signal-to-noise ratio too poor, sample preparation too complex or sample size too large to be of good service.

Now, researchers at the University of Illinois have demonstrated a method for simultaneous structural and chemical characterization of samples at the femtogram level (a femtogram is one quadrillionth of a gram) and below.

The measurement technique combines the extraordinary resolution of atomic force microscopy and the excellent chemical identification of infrared spectroscopy.

We demonstrated that imaging, extraction and chemical analysis of femtogram samples can be achieved using a heated cantilever probe in an atomic force microscope, said William P. King, a Kritzer Faculty Scholar and professor of mechanical engineering.

King and colleagues describe the technique in a paper accepted for publication in the journal Analytical Chemistry, and posted on its Web site.

The new technique hinges upon a special silicon cantilever probe with an integrated heater-thermometer. The cantilever tip temperature can be precisely controlled over a temperature range of 25 to 1,000 degrees Celsius.

Using the cantilever probe, researchers can selectively image and extract a very small sample of the material to be analyzed. The mass of the sample can be determined by a cantilever resonance technique.

To analyze the sample, the heater temperature is raised to slightly above the melting point of the sample material. The material is then analyzed by complementary Raman or Fourier transform infrared spectroscopic imaging, which provides a molecular characterization of samples down to femtogram level in minutes.

Fourier transform infrared and Raman spectroscopic imaging have become commonplace in the last five to ten years, said Rohit Bhargava, a professor of bioengineering. Our method combines atomic force microscopy with spectroscopic imaging to provide data that can be rapidly used for spectral analyses for exceptionally small sample sizes.

To clean the tip for reuse, the tip is heated to well above the decomposition temperature of the sample a technique similar to that used in self-cleaning ovens.

Since the tip can be heated to 1,000 degrees Celsius, most organic materials can be readily vaporized and removed in this manner, King said.

As a demonstration of the technique, the researchers scanned a piece of paraffin with their probe, and removed a sample for analysis. They then used Raman and Fourier transform infrared spectroscopy to chemically analyze the sample. After analysis, the paraffin was removed by thermal decomposition, allowing reuse of the probe.

We anticipate this approach will help bridge the gap between nanoscale structural analysis and conventional molecular spectroscopy, King said, and in a manner widely useful to most analytical laboratories.


'/>"/>

Contact: James E. Kloeppel
kloeppel@uiuc.edu
217-244-1073
University of Illinois at Urbana-Champaign
Source:Eurekalert

Related biology technology :

1. Mr. Richard Decker Appointed Technical Director of Edgewood Chemical Biological Center
2. NIH collaborates with EPA to improve the safety testing of chemicals
3. Merial to Screen Chimerix Chemical Library for Animal Health Drug Leads
4. The Tauri Group LLC Awarded U.S. Department of Homeland Security Chemical and Biological Early Detection Systems Program Office Support Contract
5. ADM Forms Industrial Chemicals Group
6. Isis Awarded $1.5 Million NIH Grant to Improve Chemical Properties of RNAi-Based Therapeutics
7. Vicus Therapeutics to Present at the 234th American Chemical Society National Meeting in Boston, MA
8. TorreyPines Therapeutics Reports Fourth Quarter and Full Year 2007 Financial Results and Highlights
9. Neogen Reports 34% Increase in Net Income, 20% Increase in Revenues
10. Derma Sciences MEDIHONEY(TM) Profiled in Several Television News Health Reports
11. Cardiogenesis Reports Fourth Quarter and Full Year 2007 Results
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/8/2016)... Dec. 8, 2016 Savannah River Remediation ... and selected NewTechBio,s NT-MAX Lake & Pond ... beneficial bacteria, in conjunction with Hexa Armor/ Rhombo ... with National Pollutant Discharge Elimination System requirements. ... a steady history of elevated pH levels, above ...
(Date:12/8/2016)...  Partnering to fuel Philadelphia,s ... Southeastern Pennsylvania (" Ben Franklin ... Independence Blue Cross; and Safeguard Scientifics ("Safeguard") (NYSE: ... $6 million funding initiative over a four year period ... to a burgeoning economic vitality in digital health, ...
(Date:12/7/2016)... San Diego (PRWEB) , ... December 07, 2016 ... ... safety data from its phase I/II dose escalation and expansion clinical trial for ... 2016 in Vienna, Austria. The purpose of the trial was to determine the ...
(Date:12/7/2016)... ... December 07, 2016 , ... Huffman ... has become a Wonderware Certified System Integrator Partner. Huffman Engineering is the ... Software. , “The System Integrator Partner certification gives customers confidence that our engineers ...
Breaking Biology Technology:
(Date:12/6/2016)... , Dec. 6, 2016 Securus ... justice technology solutions for public safety, investigation, corrections ... jointly announced today a five (5) year funding ... agreement to expand the rehabilitation and reentry support ... PEP History Established in 2004, the Prison Entrepreneurship ...
(Date:11/30/2016)... CHICAGO , Nov. 30, 2016  higi ... a new partnership initiative targeting national brands, industry ... and reward their respective audiences for taking steps ... Since its inception in 2012, higi has built ... US, impacting over 38 million people who have ...
(Date:11/24/2016)... 23, 2016 Cercacor today introduced Ember TM ... trainers non-invasively measure hemoglobin, Oxygen Content, Oxygen ... Respiration Rate in approximately 30 seconds. Smaller than a ... immediate access to key data about their bodies to ... regimen. Hemoglobin carries oxygen to muscles. ...
Breaking Biology News(10 mins):