What does this do? Atomic force microscropy

Several high resolution imaging techniques have been used over vastly diverse disciplines in science and engineering—from microscale with our light microscope to nanoscale with electron- or X-ray beam-mediated imaging techniques. These have been considered as routine laboratory techniques in order to visualize the micro- to nano-scale features of a certain material. How about seeing an actual bond?

AFM, or atomic force microscopy, have been recently been making news in the scientific community as it was used by two different groups to image actual bonds. This microscopic technique is based on a scanning probe, a cantilever with a tip. The tip is lowered closer to the surface of the sample until the forces between the tip to the surface are enough to cause a deflection in the cantilever, which is then correlated to a ‘signal’ that is processed to construct the image of the surface. It runs in either contact or non-contact mode, depending on the characteristics of the sample to be analyzed.

Just a month ago, researchers from China’s National Center for Nanoscience and Technology have published AFM images showing the first image of hydrogen bonds. The image was for 8-hydroxyquinoline, deposited on a copper surface. This is definitely groundbreaking, as this is showing that these bonds with weaker interactions than covalent bonds can also be visualized using this technique. This proves that AFM can be used as a tool to characterize submolecular features.



Earlier this year, another group at the University of California Berkeley have also used AFM in order to monitor a reaction. The group used oligo-(phenylene-1,2-ethynylene), immobilized the molecule on a silver substrate, and monitored the products upon heating. As a routine, organic chemists typically monitor a reaction just by thin layer chromatography (TLC), looking at how the spots develop in the plates over time. Imagine if this technique becomes a routine tool for synthetic chemists, just like NMR or MS— without a doubt, it would definitely revolutionize the way we confirm products by seeing actual bond forming and breaking.









The field seems to be more and more exciting, and maybe we just have to wait for another groundbreaking AFM news before the year ends. Given how direct and informative the images are that we can take from this technique, hopefully, researchers will be able to find a way to make it as a routine synthetic characterization tool someday. This will not only help synthetic chemists, but also materials scientists and other researchers that delve on nanotechnology.

Here’s the link to the papers, for reference:



Herdeline Ann Ardoña is a second year graduate student in the Department of Chemistry under Professor J.D. Tovar, co-advised by Professor Hai-Quan Mao.

Lindau 2013: Mingling with Nobel Laureates

During the first week of July 2013, 34 science Nobel Prize winners congregated on the island of Lindau, Germany to meet and mentor the next generation of leading researchers. 625 undergraduate, graduate, and postdoctoral students from 78 countries were invited to attend this exclusive meeting. I was very lucky to be among them!

The Lindau Nobel Laureate Meeting has been held annually since 1951 and rotates among the Nobel Prize categories of chemistry, physics, physiology and medicine, and economics. This year’s meeting was devoted to chemistry. The Lindau Mediatheque is a great resource for meeting lectures, abstracts, and programs. The database lists all of this year’s attending Laureates, along with the years and disciplines in which they won the Nobel Prize.

U.S. researchers explore the island city of Lindau, Germany.

U.S. researchers explore the island city of Lindau, Germany.

Conference mornings were spent in widely-attended and inspiring lectures by the Laureates, while the afternoons involved break-out sessions where we could asks the Laureates our questions in a more intimate setting. I learned the processes through which many of the Nobel-prize winning discoveries were made and where some of the Laureates were when they received the infamous phone call informing them that they had been awarded the Prize. The conference’s U.S. delegation consisted of approximately 70 graduate students, and our organizing partner, Oak Ridge Associated Universities, was able to score us some great additional interaction opportunities with a few of the Laureates. We had our own dinner parties arranged with Brian Kobilka (Chemistry, 2012) and Steven Chu (Physics, 1997, and former U.S. Secretary of Energy). I had the pleasure of sitting next to Akira Suzuki (Chemistry, 2010) during an extravagant international get-together dinner sponsored by the Republic of Korea.

A panel of Nobel Laureates and scientists discusses the importance of communication in science. Speaking in this photo is Ada Yonath (far left), who won the Nobel Prize for Chemistry in 2009 for her studies on the structure and function of the ribosome.

A panel of Nobel Laureates and scientists discusses the importance of communication in science. Speaking in this photo is Ada Yonath (far left), who won the Nobel Prize for Chemistry in 2009 for her studies on the structure and function of the ribosome.

The Laureates were treated like celebrities on the island of Lindau. They were each gifted their own luxury car for the week, and personal drivers shuttled them between conference events. Students vied for their pictures and autographs like they were rock stars! My favorite day of the conference incorporated a boat trip to Mainau, another German island in Lake Constance. The scenic two hour sail on a giant cruise ship included food, drink, and even dancing with the Laureates and their spouses. Once on the island of Mainau, we toured spectacular gardens and enjoyed an authentic Bavarian lunch.

From meeting science “superstars” to networking with students from around the globe and exploring a beautiful island city, I can’t speak highly enough of the remarkable experience. For information about how to apply to be a part of the U.S. delegation for the 2014 Lindau Meeting, which will focus on physiology and medicine, visit http://www.orau.org/lindau/.

Story by Allison Chambliss, who is entering her fifth year as a PhD student in the laboratory of Denis Wirtz in the Department of Chemical and Biomolecular Engineering.


Johns Hopkins opens mind-blowingly beautiful teaching labs

When I was an undergraduate at [insert state university name here] most of the biology and chemistry teaching labs we undergrads worked in were purely utilitarian spaces for bench work and all had seen better days. In fact, they looked more like my high school science labs.  My high school labs might have been nicer.

New Undergraduate Teaching Labs. (Photo by Mary Spiro)

New Undergraduate Teaching Labs. (Photo by Mary Spiro)

But there is no reason why even lower level science should not be taught in an aesthetically pleasing space. For some undergraduates, lower level science courses are a requirement that must be knocked off the graduation to-do list. Why not make the experience more exciting?

Johns Hopkins University has constructed 105,000 square feet of new undergraduate laboratory teaching space on the far side of Mudd and Levi Halls on the Homewood campus. The space beautifully integrates into the natural surroundings offered by the Buffano Sculpture Gardens. The open feel is extremely important, I think, because it allows so much natural like to come in  that it could make that time in lab section, which can seem never-ending, into something much more tolerable–even enjoyable.

Undergrads studying chemistry, biology, biophysics, neuroscience and psychological and brain sciences will be using the 20 labs that were created with the new space. The philosophy behind the design of the building is to encourage cross disciplinary collaboration, which as many know is something that Johns Hopkins Institute for NanoBioTechnology strives for in all of its endeavors. It is nice to see that same kind of sentiment carried out in a physical way in this new campus structure.

For now, the addition is just being called the UTL (undergraduate teaching laboratories) building. The core of the structure includes space for nuclear magnetic resonance imaging and tissue and cell culture. Lab space connects to the adjacent academic buildings via mingling areas, ample seating, faculty offices, a large biology research lab, a computer lab, seminar rooms, a coffee bar and more. 

I recommend walking over to the UTL yourself and having a look around if you are on the Homewood campus. If not you can watch this video. It will make you want to register for a chemistry class like a freshman. No, joke. This building is a work of art and an amazing addition to the already beautiful Homewood campus.

Read the story about the new laboratory building here.

What’s on the horizon for regenerative medicine?

Organo-electric nanowires.  (Tovar Lab/JHU)

Organo-electric nanowires. (Tovar Lab/JHU)

Editor’s Note: The following is a summary of one of the talks from the 2013 Nano-bio Symposium hosted by Johns Hopkins Institute for NanoBioTechnology held May 17. This summary was written by Christian Pick, a doctoral candidate in the chemical and biomolecular engineering laboratory of Joelle Frechette. Look for other symposium summaries on the INBT blog.

The fundamental goal of regenerative medicine is to allow the body to restore normal function to damaged or diseased tissues. Tissue scaffolds provide a structure for cells to grow on to accomplish this task. The pinnacle of scaffold function would be for the tissue grown from a scaffold to be completely indistinguishable from natural, undamaged tissue.

In order to improve scaffolds, researchers need to better understand how scaffolds interact with the body. Peter Gabriele, Director of Emerging Technology at Secant Medical, discussed FT-IR microscopy,  which is a unique tool that can help researchers with this very task.

Fourier transform infrared (FTIR) spectroscopy is a powerful technique for analyzing the chemical identity of materials. FTIR spectroscopy has been used for years in forensic analysis for identifying unknown samples. FTIR microscopy combines the functionality of FTIR spectroscopy with optical microscopy.

For the field of regenerative medicine, this means that the surface functionality of a scaffold can be mapped and studied throughout its entire lifetime: from production through degradation in-vivo. For instance, FTIR microscopy can be used to analyze surface modifications made to a scaffold during fabrication.

Additionally, it can be used to track tissue formation in implanted scaffolds. As an example, Mr. Gabriele described studies on “biorubber” or poly(glycerol sebacate) (PGS). FTIR microscopy has been used to identify collagen integration within the polymer during implantation as well as map the erosion of the material once implanted. Through the use of tools such as FT-IR microscopy, researchers can continue to expand the functionality of tissue scaffolds.

Secant Medical

Watch a video about INBT’s current research efforts in the realm of regenerative medicine here.

Lindau: where the Nobel Laureates gather

If you want to rub elbows with Nobel Laureates, the place to be this week is Lindau, Germany. Three of the four Johns Hopkins University graduate students attending the 63rd Annual Lindau Nobel Laureate meeting, which is dedicated to chemistry thie year, work in Institute for NanoBioTechnology affiliated laboratories. The meeting runs from June 30 to July 5 and will host more than 550 young researchers from 78 countries.

Allison Chambliss, a doctoral student in chemical and biomolecular engineering from the laboratory of Denis Wirtz; Sravanti Kusuman, a doctoral student in biomedical engineering from the laboratory of Sharon Gerecht; and Allix Sanders, a graduate student in chemistry from the laboratory of J.D. Tovar,  were chosen to attend along with 71 other top U.S. graduate student researchers. This year’s group is sponsored by the U.S. Department of Energy, Mars, Incorporated, the National Science Foundation, and the Oak Ridge Associated Universities (ORAU).

Before she left, Allison said she was excited about the opportunity to interact with successful and well known researchers, which is harder to do at big conferences. Essentially, she and the others will be chatting with the “rockstars” of science. Allison was able to attend despite also having a summer internship with Novozyme in Raleigh, NC, where she is working in their R&D department on biofuels.

“I liked hearing about how it was so interactive and that there will be people from all over the world. And then the fact that there will be Nobel Laureates, you don’t get the chance to meet someone like that every day, “ Allison said. She also sees this as an opportunity to network in case she wants to do a postdoctoral fellowship in another country. “I will be meeting people from labs all over the place and also people in both academia and industry.”

Allison’s current research in the Wirtz lab involves using high-throughput cell phenotyping to look at the physical characteristic of cells on a single cell basis and how physical attributes can impact a cell genetically. Allison did her undergraduate work at Virginia Tech.

Sravanti’s did her undergraduate work at MIT. Her research in the Gerecht lab involves using pluripotent stem cells and a specially engineered synthetic matrix to grow a micro-vasculature (tiny blood vessels).

“These are the seminal leaders in their field, and in many cases, they are the ones that created their fields, so I just think it will be great to learn the science from their standpoint,” Sravanti said. “You know, like what obstacles did they have to overcome to prove their point, since all their findings would be really novel.”

She is also interested in learning what inspires and keeps these leading figures going. “This is also a more intimate setting,” Sravanti added. “There are lectures in the morning but in the afternoon there are smaller roundtable discussions where you can get more intimate with whichever Nobel Laureate you choose to talk to.

Allix Sanders is working on a project in the Tovar lab that incorporates large, unique chromophores comprised of extended pi-conjugated networks into peptide chains. Following self-assembly, the photophysical characterizations of the supramolecular polymers will be investigated with the future goal of creating useful electronic materials. Allix did her undergraduate studies at Lebanon Valley College.

The fourth Johns Hopkins University student is Joseph Schonhoft, a doctoral student in the biophysics department, which is part of the Krieger School of Arts and Sciences. He works in the laboratory of James Stivers at the School of Medicine. His research involves facillitated diffusion mechanisms of DNA repair enzymes.

According to information from ORAU, Nobel Laureates have annually convened in Lindau since 1951 to have open and informal meetings with students and young researchers from around the world. Laureates and students exchange ideas, discuss projects and build international networks throughout the week. All attendees must pass through a competitive application and selection process managed by the Council for the Lindau Nobel Laureate Meetings. Throughout the week, the 35 participating Laureates will lecture in the mornings on the topic of their choice related to chemistry and participate in smaller question and answer sessions in the afternoons. Students will also interact with the Laureates and other international students during the week for more informal discussions. This year, with the addition of science master classes, a select few researchers will have the opportunity to present their research to a Nobel Laureate and a small group of their peers.

For more information regarding the 63rd Lindau Meeting of Nobel Laureates and Students, visit the ORAU–Lindau website. The ORAU-Lindau website and all logistical arrangements for the participants are being administered by the Oak Ridge Institute for Science and Education, a DOE institute managed by ORAU.

Baby crystal discovery big step for nanoscience

How small can a chemical compound be and still retain the properties of that same compound in bulk? With computer models and laboratory experiments, researchers at Johns Hopkins University, collaborating with those at McNeese State University in Lake Charles, LA, and the University of Konstanz in Germany, have determined the smallest crystal configuration, or as they call it, a “baby crystal,” of lead sulfide.

Predicted dimensions of nano-blocks achieved by growing individual (PbS)32 baby crystals. STM images confirmed these dimensions. (Illustration courtesy Bowen Lab)

The team first determined the structure theoretically with computer modeling. They then proved their model experimentally in the laboratory by carefully depositing clusters of (PbS)32 onto a graphite surface, where the clusters could migrate together into larger nanoscale units.

“By using scanning tunneling microscope (STM) images to measure the dimensions of the resultant lead sulfide nano-blocks, we confirmed that (PbS)32 baby crystals had indeed stacked together as predicted by theory,” said Kit Bowen Jr., the E. Emmet Reid Professor in the Department of Chemistry at Johns Hopkins. Bowen worked on the project with, Howard Fairbrother, also a professor of chemistry. Both are affiliated faculty members of the Institute for NanoBioTechnology.

Bowen explained that the baby crystal needed just 32 units of lead sulfide to “exhibit the same structural coordination properties” of the same material at macroscale. Nanoblocks this small would have photovoltaic (solar power) applications.

“Determining the size of nano and sub-nano scale assemblies of atoms or molecules at which they first take-on recognizable properties of the same substance in the macroscopic world is an important goal in nanoscience,” Bowen said.

Their research can be found in the Journal of Chemical Physics and The Virtual Journal of Nanoscale Science & Technology. A Department of Energy grant funded this research.

 The Virtual Journal of Science & Technology

Bowen Lab