Navigation Links
No compromises: JILA's short, flexible, reusable AFM probe
Date:4/9/2014

JILA researchers have engineered a short, flexible, reusable probe for the atomic force microscope (AFM) that enables state-of-the-art precision and stability in picoscale force measurements. Shorter, softer and more agile than standard and recently enhanced AFM probes, the JILA tips will benefit nanotechnology and studies of folding and stretching in biomolecules such as proteins and DNA.

An AFM probe is a cantilever, shaped like a tiny diving board with a small, atomic-scale point on the free end. To measure forces at the molecular scale in a liquid, the probe attaches its tip to a molecule such as a protein and pulls; the resulting deflection of the cantilever is measured. The forces are in the realm of piconewtons, or trillionths of a newton. One newton is roughly the weight of a small apple.

The new probe design, described in ACS Nano,* is the JILA research group's third recent advance in AFM technology. JILA is jointly operated by the National Institute of Standards and Technology (NIST) and University of Colorado Boulder.

The group previously improved AFM position stability by using laser beams to sense motion** and removing the gold coating from long probe tips, or cantilevers, to enhance long-term force stability.*** However, removing the gold reduces the strength of the signal being measured, and using long cantilevers leads to other measurement problems such as slower response to dynamic events like protein unfolding.

The latest modification overcomes these and other issues, improving precision without loss of stability, speed, or sensitivity. JILA researchers used a focused ion beam to cut a hole in the center of a short commercial cantilever and thinned the remaining support structures, thereby reducing the cantilever's stiffness and friction near surfaces. The result is excellent long-term stability and improved short-term precision, respectively, in AFM force measurements.

JILA researchers also added a protective glass cap over the gold coating at the end of the cantilever to retain beneficial reflectivity, and then removed the remaining gold to gain force stability. The modified cantilever enables rapid, precise and stable force measurements across a broad range of operating frequencies.

"Previously, we had to average the Brownian (random) motion of our favorite cantilever for about 60 milliseconds to get a measurement that had a precision of 1 piconewton," JILA/NIST biophysicist Tom Perkins says. "Now, we can get the same precision in 1 millisecond or so."

JILA researchers demonstrated significant benefits for single molecule studies. For instance, the short, soft cantilevers can quickly measure abrupt changes in force when a protein unfolds. Protein folding is required for proper biological function and misfolding can lead to diseases such as Alzheimer's. The new cantilevers match the response of stiffer, unmodified cantilevers but with greater stability and precision. Force stability is crucial in this application because protein folding and unfolding rates are exponentially sensitive to tiny changes (smaller than 1 piconewton) in applied load. The new device also can track fleeting nanoscale events, including protein folding, over hundreds of secondsmuch longer periods than previously possible. The new design should also be applicable to rapid probing of the mechanical properties of materials at the nanoscale.

Significantly, the new cantilevers are robust enough to be reused for multiple days. Moreover, JILA researchers say the new design is simple and inexpensive to make, and thus, suitable for routine use.

"Amazingly, this project was spearheaded by a talented undergraduate. We hope other groups with similarly talented students will adopt these cantilevers. We certainly are," Perkins said.


'/>"/>

Contact: Laura Ost
laura.ost@nist.gov
303-497-4880
National Institute of Standards and Technology (NIST)
Source:Eurekalert  

Related biology news :

1. Oil and water: An icy interaction when oil chains are short, but steamy when chains are long
2. Researchers create flexible, nanoscale bed of nails for possible drug delivery
3. Robotic arm probes chemistry of 3-D objects by mass spectrometry
4. New probes from Scripps research quantify folded and misfolded protein levels in cells
5. Researchers use genetic signals affecting lipid levels to probe heart disease risk
6. Global Cancer Biomarkers Market 2012-2016 with Agilent Technologies Inc., Gen-Probe Inc. and Astellas Pharma US Inc. Dominating
7. IU-designed probe opens new path for drug development against leading STD
8. Stanford scientists probe abandoned mine for clues about permanent CO2 sequestration
9. Light and nanoprobes detect early signs of infection
10. Light-emitting bioprobe fits in a single cell
11. Listening to cells: Scientists probe human cells with high-frequency sound
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
No compromises: JILA's short, flexible, reusable AFM probe
(Date:4/13/2016)... 2016  IMPOWER physicians supporting Medicaid patients in ... clinical standard in telehealth thanks to a new partnership ... platform, IMPOWER patients can routinely track key health measurements, ... index, and, when they opt in, share them with ... a local retail location at no cost. By leveraging ...
(Date:3/23/2016)... March 23, 2016 ... Sicherheit Gesichts- und Stimmerkennung mit Passwörtern ... (NASDAQ: MESG ), ein führender Anbieter ... Unternehmen mit SpeechPro zusammenarbeitet, um erstmals dessen ... wird die Möglichkeit angeboten, im Rahmen mobiler ...
(Date:3/18/2016)... -- --> --> Competitive ... Unmanned Vehicles, Physical infrastructure and Perimeter Surveillance & Detection Systems ... security market and the continuing migration crisis in the ... has led visiongain to publish this unique report, which ... defence & security companies in the border security market ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... ... 2016 , ... Proove Biosciences, Inc ., the commercial ... of the Proove Health Foundation . The Foundation is a non-profit organization ... of personalized medicine for tackling the nation’s most-pressing healthcare epidemics. As part of ...
(Date:4/29/2016)... ... ... Intelligent Implant Systems announced today that the two-level components for the Revolution™ ... States. These components expand the capabilities of the system and allow Revolution™ to ... of 2015, the company has seen significant sales growth in 1Q 2016, and the ...
(Date:4/28/2016)... ... April 28, 2016 , ... Next week on May ... its first-in-class technologies for tissue stem cell counting and expansion to gene-editing scientists ... Reprogramming & CRISPR-based Genome Engineering in Burlington, Massachusetts. , The attention of most ...
(Date:4/27/2016)... ... ... The Pittcon Organizing Committee is pleased to announce that Charles “Chuck” Gardner was ... since 1987. Since then, he has served in a number of key leadership positions ... the program and exposition committees. In his professional career, Dr. Gardner is the director ...
Breaking Biology Technology: