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Molecular Data-Storage System Encodes Information with Peptides

Using a set of 32 small peptides, researchers have developed a chemical coding system that could offer a simple approach to molecule-based data storage.

Conventional data stores, including hard drives and tape, that encode information by magnetizing tiny grains can be bulky and expensive to maintain. In principle, molecules may be a more efficient way to archive vast amounts of data over the long term in a low-cost format that consumes far less energy and lasts for centuries.

Researchers have previously used the sequence of bases—A, G, C, and T—in strands of synthetic DNA to represent the digital ones and zeros of everyday computing. Researchers have already stored books and videos this way and decoded them with DNA sequencers. But DNA synthesis is slow and expensive, and recording more information requires building fresh strands each time.

A team led by George M. Whitesides of Harvard University has now developed an alternative approach to molecular data storage that encodes information using 32 short peptides. “The virtue is that it can be done pretty rapidly and really quite inexpensively,” Whitesides says.

The system uses a robotic dispenser to transfer peptides from stock solutions onto a flat metal plate covered with 1,536 gold spots. These 1.25 mm wide spots carry linker molecules that bind to the peptides, each of which contains up to 7 amino acid residues and represents a unit of binary data, known as a bit. If a particular peptide is fixed to a spot, it represents a digital one; if it is absent, the bit’s value is zero. With 32 possible peptides and 8 bits to a byte, the system can encode 4 bytes of data onto each gold spot.

To read the data, the researchers use matrix-assisted laser desorption ionization time-of-flight mass spectrometry to dislodge traces of the peptides and linkers from a spot. Since each peptide has a different mass, the team’s software can automatically decode the resulting mass spectrum into a series of ones and zeros. Scanning each spot in turn allows the system to read out 4 bytes of data at a time and reconstruct the whole dataset. “I think it’s highly innovative; it’s really out of the box,” says Tom F. A. de Greef of the Eindhoven University of Technology, who works on DNA-based data systems.

Whitesides’s team has used the method to encode 400 kilobits of text—Richard Feynman’s famous lecture, ”There’s Plenty of Room at the Bottom”—and store images such as the woodblock print entitled Under the Wave off Kanagawa. The system can write data onto the plates at a rate of 8 bits per second and read it at 20 bps, reliably recovering more than 99% of the information. Peptides dislodged from the spot can never be read again, but the team estimates that enough will remain for multiple scans.

The researchers say that their method is much faster than DNA data storage, which has an average write speed of about 0.001 bps, and it also avoids using any of the reagents needed for synthesis and sequencing. “Synthesis is just intrinsically slow,” Whitesides says.

Speed isn’t everything, though. “One of the reasons people want to do molecular data storage is that you can have a petabyte [1015 bytes] of data in a small test tube, so there’s almost no physical footprint,” de Greef says.

In contrast, the spacing of the gold spots in Whitesides’s system means that it currently stores a mere 64 bytes per square centimeter. But the researchers say they could boost this to megabytes by clustering the gold spots closer together and using a larger set of molecules. Meanwhile, an inkjet printer could write the data much faster, and incorporating cheaper molecules, such as alkanethiols, could cut costs. “Any molecule that can be immobilized and has a unique mass is a candidate for storing information with this approach,” says Milan Mrksich of Northwestern University, who was part of the research team.

Whitesides thinks that the method could eventually be used for secure, long-term data archiving of patient records or financial information, for example. For now, his team is exploring variations on the technique to optimize its speed, cost, and data density.

This article is reproduced with permission from C&EN (© American Chemical Society). The article was first published on May 1, 2019.

Surface Water Protection Program for Pesticide Use in California

The increasing use of the newer pesticides such as the pyrethroids, neonicotinoids, and fipronil has resulted in their ubiquitous occurrence in surface waters and led to observations of adverse effects on aquatic organisms. The widespread contamination has stimulated active discussions and research on monitoring, aquatic toxicology, risk assessment, modeling, mitigation, and regulatory efforts to minimize contamination and protect environmental integrity.

There are only a few programs that consistently monitor for pesticides in surface water in the United States, namely the U.S. Geological Survey’s National Water-Quality Assessment Program and the monitoring programs in Minnesota, Washington, North Dakota, Oregon, and California. California likely has the most comprehensive and sustained surface water protection program for pesticides, implemented to address the large amount of pesticide use (94.8 million kg in 2016) for agricultural and urban pest control and aimed to protect surface water quality for the benefit of human and aquatic health. The California Department of Pesticide Regulation (CDPR) conducted its first surface water monitoring study in 1981 and officially established the Surface Water Protection Program (SWPP) in 2000.

The SWPP has evolved to become a holistic scientific program that implements components of pollution prevention, monitoring, modeling, mitigation, research, education, outreach, and regulation. The program has a clear mission and vision to protect surface water quality under the general pesticide regulatory authorities and mandates in California.

Prevention

A key component to protecting surface water quality is to prevent a new pesticide product that could adversely affect aquatic and benthic organisms from being used in California. The SWPP conducts evaluations during the pesticide registration process to identify products that could pose high adverse risks to the state’s aquatic environments when used according to the product label. The Pesticide Registration Evaluation Model (PREM) can be used to evaluate most pesticide products that the SWPP receives for potential impacts to aquatic and benthic organisms in order to protect the environment and human health. PREM is conducted in two stages: (1) initial screening, and (2) refined modeling with focus on aquatic application, rice application, urban scenarios, high risk agricultural use patterns, and pesticide degradates.

Monitoring

Once a pesticide is registered for use in California, the use amount and its pattern is evaluated by running the Surface Water Monitoring Prioritization Model (SWMP). SWMP is developed to prioritize pesticides for surface water monitoring in agricultural and urban areas of California. To generate the monitoring priority list of pesticide ingredients and their degradates, the model incorporates pesticide use and toxicity data, as well as chemical properties, monitoring results, and application information.

Mitigation

Pesticides detected at high frequencies and at concentrations exceeding U.S. Environmental Protection Agency (EPA) aquatic life benchmarks are targeted for mitigation actions. Collaborative educational and outreach events are initiated to pesticide users for taking measures to mitigate pesticide runoff. More specifically, engaging with the pesticide registrants and professional user groups on taking voluntary product stewardship measures and, when necessary, follow up with a formal reevaluation process or provide suggested label changes. Mitigation could be in the form of issuing permit conditions with use restrictions (particularly to address agricultural sources), product label changes by registrant, or regulations with restrictions including those related to limitation on application methods, timing of application, target sites, environmental conditions, formulation, a buffer zone to sensitive sites, for example.

This post is an excerpt from Pesticides in Surface Water: Monitoring, Modeling, Risk Assessment, and Management‘.

Editors: Kean S. Goh, Jay Gan, Dirk F. Young, Yuzhou Luo
Publication Date (Web): March 26, 2019
Copyright © 2019 American Chemical Society

Read a free sample chapter: Surface Water Protection Program for Pesticide Use in California

Organometallics Congratulates the Recipients of the 2019 RSEQ-GEQO Awards

The Spanish Royal Society of Chemistry’s Specialized Organometallic Chemistry Group announced the recipients of its annual awards recognizing excellence in organometallic chemistry. The Spanish organometallics community has a rich history and a close association with Organometallics, the American Chemical Society’s world-leading journal publishing organometallic chemistry research. Organometallics Editor-in-Chief Paul J. Chirik extends his congratulations to the winners of this year’s RSEQ-GEQO awards on behalf of the journal and its editorial team.

Professor Miguel Ángel Ciriano of the University of Zaragoza is the recipient of the Rafael Usón Medal. Professor Ciriano, who received his graduate training under Professor Usón, is being recognized for his role as a pioneering researcher in the field of organometallic chemistry, particularly for his innovative work on the synthesis and reactivity of rhodium and iridium complexes. His notable recent work includes catalysts for the activation and transfer of oxygen to an olefin with 100% atom economy and selective synthesis of E-enynes.

Professor Eva Hevia of the University of Bern has received the GEQO Prize for Excellence in Research for the novelty and relevance of her work on main-group metals. Her recent contributions include the use of cooperative bimetallic compounds for the activation of pharmaceutically relevant organic molecules, as well as the advancement of new methods that replace the use of toxic organic solvents with more sustainable and biorenewable systems.

Dr. Arkaitz Correa of the University of the Basque Country earned the GEQO Prize for Young Researchers. During his training, Dr. Correa has carried out innovative and important work in the development of metal-catalyzed reactions for organic synthesis. In his still short independent career, he is focusing on the functionalization of C-H bonds within peptide and heterocyclic frameworks via sustainable metal catalysis.

“On behalf of the Organometallics editorial team, I would like to congratulate these three outstanding chemists recognized with this year’s RSEQ-GEQO awards,” Professor Chirik says. “These prizes are well-deserved and reflect the quality and diversity of the organometallic chemistry carried out by Spanish researchers. We hope to see this and other outstanding chemistry from Spain in future issues of Organometallics.”

Recent ACS Publications by the 2019 RSEQ-GEQO Award Recipients:

Agostic versus Terminal Ethyl Rhodium Complexes: A Combined Experimental and Theoretical Study
Organometallics, 2016, 35, 5, 799-808
DOI: /10.1021/acs.organomet.6b00036
***
Nucleophilicity and P–C Bond Formation Reactions of a Terminal Phosphanido Iridium Complex
Inorg. Chem., 2016, 55, 2, 828-839
DOI: 10.1021/acs.inorgchem.5b02301
***
Trans-Metal-Trapping Meets Frustrated-Lewis-Pair Chemistry: Ga(CH2SiMe3)3-Induced C–H Functionalizations
Inorg. Chem., 2017, 56, 15, 8615-8626
DOI: 10.1021/acs.inorgchem.7b00549
***
Structurally Defined Zincated and Aluminated Complexes of Ferrocene Made by Alkali-Metal Synergistic Syntheses
Organometallics, 2015, 34, 11, 2580-2589
DOI: 10.1021/om5012352
***
Co-Catalyzed C(sp3)–H Oxidative Coupling of Glycine and Peptide Derivatives
Marcos San SegundoItziar GuerreroArkaitz Correa*Orcid
Org. Lett., 2017, 19, 19, 5288-5291
DOI: 10.1021/acs.orglett.7b02567
***
Selective C(sp2)–H Halogenation of “Click” 4-Aryl-1,2,3-triazoles
Org. Lett., 2017, 19, 4, 962-965
DOI: 10.1021/acs.orglett.7b00275

Revealing How Enzymes Turn a Toxin Into a Potential Painkiller

Saxitoxin—a compound made by marine microbes that can contaminate shellfish—is a toxin so potent that minute quantities can prove deadly. Its mode of action means that less toxic versions have potential as nonaddictive painkillers, but the molecule’s complexity makes it tricky to modify with chemical reagents. Now, researchers have worked out how a suite of microbial enzymes can make the molecule less toxic, taking a first step toward biocatalytic development of new drugs based on saxitoxin and other shellfish toxins.

Saxitoxin is a large, clunky molecule with seven nitrogens. It acts by binding strongly to voltage-gated sodium channels that sit in cell membranes and initiate and transmit nerve signals. When saxitoxin binds to these channels, it over-excites cells and blocks nerve impulses. A less potent version that causes a milder effect could potentially tamp down pain sensations without hindering other nerve signals. But the compound’s therapeutic potential has been largely untapped because its complex chemical structure is difficult to tweak, says Alison Narayan of the University of Michigan, who led the new work.

But what’s difficult to do with laboratory reagents can often be easily accomplished by enzymes in nature. Previous studies have identified enzymes in marine microbes, scallops, and other shellfish that can add sulfur-containing groups to saxitoxin to make less toxic versions. To understand how the enzymes make these substitutions and what substrates they target, Narayan and her colleagues turned to three enzymes produced by different types of cyanobacteria, one of the organisms that can produce saxitoxins, and expressed the genes for these enzymes in Escherichia coli.

They purified the enzymes and studied how each one acted individually on a range of saxitoxin-related compounds. The reactions resulted in molecules that had sulfur groups in multiple locations.

They also performed a cascade, or one-pot, reaction in which all three enzymes were added to saxitoxin at the same time. “Typically, with chemical synthesis you form one bond, isolate the product, purify it and then set up the next reaction,” Narayan explains. “We were pleased to be able to do these types of cascades, which allow you to really quickly make modifications to a molecule like saxitoxin.”

The team then tested the potency of the sulfur-containing compounds on sodium channels within cell membranes derived from mouse brains and compared them with saxitoxin. The researchers first saturated all the channels with radioactively labeled saxitoxin and then treated them with the derivatives to see how much would be needed to compete with and remove the bound saxitoxin. They found that compounds with more sulfur groups were less potent—and thus less toxic—since more of these compounds were needed to remove bound saxitoxin. These lower potency compounds could be further developed as potential painkillers, because similar toxin-based compounds are already in clinical trials as alternatives to opioids for treating acute post-surgery pain.

“This study is the first to show the sequence of enzyme reactions and intermediates” needed to make these less toxic variants, says Bradley Moore of the University of California, San Diego, who studies marine microbial products but was not involved with this study.

“It’s always interesting to see how nature does the chemistry,” says Yi Tang of the University of California Los Angeles. Constructing these molecules starting with their basic building blocks isn’t practical because they are so complex, he adds. “Enzymatic reactions have fewer steps and are easier to scale up.”

This article is reproduced with permission from C&EN (© American Chemical Society). The article was first published on April 23, 2019.

ACS Editors’ Choice: Organic Charge-Coupled Device — and More!

This week: Organic charge-coupled device — and more!

Each and every day, ACS grants free access to a new peer-reviewed research article from one of the Society’s journals. These articles are specially chosen by a team of scientific editors of ACS journals from around the world to highlight the transformative power of chemistry. Access to these articles will remain open to all as a public service.

Check out this week’s picks!
***
Cytocompatibility of Molecularly Imprinted Polymers for Deodorants: Evaluation on Human Keratinocytes and Axillary-Hosted Bacteria

ACS Appl. Bio Mater., 2019, ASAP
DOI: 10.1021/acsabm.9b00388
***
Organic Charge-Coupled Device

ACS Photonics, 2019, ASAP
DOI: 10.1021/acsphotonics.9b00596
***
Enhanced Mechanical Damping in Electrospun Polymer Fibers with Liquid Cores: Applications to Sound Damping

ACS Appl. Polym. Mater., 2019, ASAP
DOI:10.1021/acsapm.9b00352
***
Golden Opportunity: A Clickable Azide-Functionalized [Au25(SR)18]− Nanocluster Platform for Interfacial Surface Modifications

J. Am. Chem. Soc., 2019, ASAP
DOI: 10.1021/jacs.9b05182
***
Revisiting Trade-offs between Rubisco Kinetic Parameters

Biochemistry, 2019, ASAP
DOI: 10.1021/acs.biochem.9b00237
***
Are Fluorescent Silicon Nanoparticles Formed in a One-Pot Aqueous Synthesis?

Chem. Mater., 2019, ASAP
DOI: 10.1021/acs.chemmater.9b01067
***
Engineering Selective Desalination Membranes via Molecular Control of Polymer Functional Groups

Environ. Sci. Technol. Lett., 2019, ASAP
DOI: 10.1021/acs.estlett.9b00351
***
Love ACS Editors’ Choice? Get a weekly e-mail of the latest ACS Editor’s Choice articles and never miss a breakthrough!

Oxytocin Analogs Show Promise for Developing Drugs for Social Behavior Challenges

Oxytocin analogs helped genetically engineered mice overcome some social impairments similar to those seen in people with autism or depression. One analog lasted for over 24 hours in the mice, while the other was a superagonist, meaning that it was more potent than natural oxytocin.

Challenges with social interactions, including face-to-face communication, can accompany depression, schizophrenia, and autism spectrum disorders. Doctors have long sought medication as a way to address these challenges, but no truly effective drug has yet been discovered. Some researchers think cell-signaling problems involving oxytocin—the peptide hormone responsible for social bonding, among other behaviors—might be a contributing factor. However, the therapeutic potential of oxytocin is difficult to study because it breaks down quickly in the body. In a new study, researchers have shown that two longer-lasting oxytocin analogs can affect social functioning for up to 24 h in mice genetically engineered to have autism- or depression-like characteristics.

The researchers found that these new compounds bind quickly to oxytocin receptors and have long-lasting action, something that has not been found before with other oxytocin analogs, says study author Haruhiro Higashida, a neuropharmacologist at Kanazawa University. Building on previous work, Higashida, medicinal chemist Satoshi Shuto of Hokkaido University, and colleagues synthesized a series of six oxytocin analogs that had either N-(p-fluorobenzyl)glycine or N-(3-hydroxypropyl)glycine replacing a proline on the oxytocin backbone.

Then the researchers tested how tightly both oxytocin and the analogs bound to human oxytocin receptors from cultured human cells. The researchers found that one of their fluorobenzyl analogs acted as a superagonist in their oxytocin binding test, which means that it bound even more strongly to the receptors than oxytocin. It’s not unusual to get a chemical with bigger effects than the natural product, Higashida says. “In this case, we unexpectedly found one analog which showed 30% higher potency, which has not been reported before in the oxytocin analog field.”

To test the duration of the analogs, the researchers injected two of the most promising ones into mice that had a genetic mutation impairing oxytocin signaling and compared them with oxytocin. They then measured the mice’s performance on a number of tests designed to demonstrate nurturing or depression-like behavior. Higashida and coworkers found that the effect of oxytocin on social behavior disappeared in the engineered mice after about 6 h. But the two analogs remained active for up to 12 h, and one of those—the hydroxypropyl analog—was still affecting the mice’s behavior at 24 hours.

However, when they tested the mouse’s blood for levels of the compound after injection, the researchers found that the fluorobenzyl analog disappeared faster than oxytocin or the hydroxypropyl analog did. They could determine the presence of the hydroxypropyl analog after 30 m and 12 h but not its exact concentration because it was below the detection limit of the instrument.

Their results in the mouse models were stunning, says Kazimierz Wisniewski, a senior scientist at the Ferring Research Institute. However, not being able to measure the longest lasting analog in the mouse’s blood was disappointing, he says. “Yes, oxytocin does something, but unless we can demonstrate that it goes to the brain in some meaningful amount and explain why the compound works and is long acting,” it’s going to be difficult to move these compounds forward into more advanced testing, he says. “I don’t think the [compounds] described here are the ones we can use for treating people, but it’s a step in the right direction.”

This article is reproduced with permission from C&EN (© American Chemical Society). The article was first published on April 25, 2019.

Play Now: Organic Letters’ Chemical Pursuits Trivia

If you follow Organic Letters on Twitter, you know there’s been a lot of buzz around the Chemical Pursuits Trivia Tournament. For those wondering what it is and how to take part, we’ll outline everything you need to know here!

Organic LettersChemical Pursuits is a month-long trivia tournament from July 15-August 16. Throughout the tournament, weekly rounds will open from Monday at 10 am – Friday at 10 am EDT.  The two participants with the highest scores at the end of the tournament will win an Amazon Echo.

Each quiz has five, multiple-choice questions, each of which has a 15 second time limit.

  • Round 1: Concluded July 19th
  • Round 2: Play at any time from until now July 26th at 10 am EDT
  • Round 3: Live July 29th at 10 am EDT
  • Round 4: Live August 5th at 10 am EDT
  • Round 5: Live August 12th at 10 am EDT

Follow Organic Letters on Twitter for weekly round links and winner announcements!

Come See ACS Publications in San Diego: August 25-28, 2019

Each ACS National Meeting & Exposition brings with it a wealth of fun activities and events from all corners of ACS Publications. The upcoming ACS Fall 2019 National Meeting & Exposition in San Diego, California, will be no exception. This meeting will explore the theme of Chemistry & Water (learn more about fundamental water chemistry in this Virtual Issue). Join ACS Publications to welcome new editors & new journals, learn from our website demos, attend some fun celebrations, and more!

Sunday, August 25th

Organic Division – Organometallics Distinguished Author Award Symposium

8:30-11:00 A.M., San Diego Convention Center, Ballroom 20A


Energy & Fuels Lectureship Award in Honor of Mark Thomas

9:00 A.M., San Diego Convention Center, Room 24C


Biochemistry Gordon Hammes Lectureship and Scholar Award Lectures

1:00–4:30 P.M., Marriott Marquis San Diego Marina, Marriott Grand Ballroom, Section 5
Reception will follow immediately after.


Journal of Organic Chemistry/Organic Letters Outstanding Publication Lectureship Symposium

1:00-5:00 P.M., San Diego Convention Center, Ballroom 20A


Inorganic Division – Organometallics Distinguished Author Award Symposium

1:30-4:30 P.M., Marina Ballroom Salon F, Marriott Marquis San Diego Marina


Physical Division – JCTC 15th Anniversary Reception

4:30-6:00 P.M., Marriott Grand Ballroom Section 12, Marriott Marquis San Diego Marina
Following the “Computational Quantum Chemistry: From Promise to Prominence: A Symposium in Honor of Henry F. Schaefer” symposium Sunday evening, join the editors of the Journal of Chemical Theory and Computation for cake and a champagne toast as the journal celebrates its 15th anniversary.


C&EN’s Talented 12 Reveal

6:00-7:00P.M., San Diego Convention Center: ACS Booth Theater
Watch the reveal of C&EN’s Talented 12 Class of 2019. These rising stars are taking on some of the world’s most daunting problems. Get more information on this event and others.

Monday, August 26th

JACS Symposium: Spotlight on the Chemistry of Water in the Journal of the American Chemical Society

8–10:30 A.M., San Diego Convention Center, Room 5A


C&EN’s Talented 12 Symposium

 8:00 A.M.-12:00P.M., San Diego Convention Center, Room 6E
Get to know C&EN’s Talented 12 Class of 2019 as they each share the motivation behind their research. Get more information and RSVP for this event, including a prize giveaway.


ACS Catalysis Lectureship Symposium

8:00 A.M., San Diego Convention Center, Room 1A


Inorganic Chemistry Lectureship Symposium

8:30 A.M.-12:00 P.M., Marriott Marquis San Diego Marina, Solana


ACS on Campus – Write it, Speak it: Effective Communications and How to Talk About Your Research 

10:00–11:00A.M., San Diego Convention Center, ACS Booth #1613

Join ACS on Campus and Professor Greg Scholes, Deputy Editor, Journal of Physical Chemistry Letters with their most highly requested presentation focusing on how to effectively communicate scientific research to the larger population


ACS Publications Website Launch Celebration

1:00—3:00 P.M., San Diego Convention Center, ACS Publications Booth
Come celebrate the redesigned ACS Publications Web Platform on Monday at the ACS Publications booth. Whether you are an ACS author, researcher, or librarian, come join us for a one-on-one demonstration of our innovative new website that was introduced earlier this year. The first 30 participants will receive an Amazon Fire TV Stick!


OPR&D Celebrates the 25th Anniversary of the Buchwald-Hartwig Amination

11:00 A.M.-12:00 P.M., San Diego Convention Center, ACS Booth Theater
In August, Organic Process Research & Development publishes a special issue honoring 25 years of the Buchwald-Hartwig Amination. This chemical reaction has had a major impact on organic chemistry for the synthesis of carbon–nitrogen bonds. It is named for Stephen L. Buchwald and John F. Hartwig, both noted authors of ACS Publications and the 2018 Recipients of the Tetrahedron Prize for Creativity in Organic Chemistry – which will be awarded in San Diego as well. Join the journal for refreshments and learn more about this issue!


Journal of Agricultural and Food Chemistry 2019 Research Article of the Year Award Lectureship Winners (AGRO)

12:55 P.M., San Diego Convention Center, Room 33C


Materials Making a Splash – Emerging Trends in Nanoscience, Materials Science & Photonics

1:00-4:00 P.M., San Diego Convention Center, Room 5A
Join us to learn more about the latest research emerging out of the fields of nanoscience, materials, and photonics, such as new electrochemical desalination technologies, organ printing for regenerative medicine, and photo-triggered drug delivery systems. Speakers include Paul Alivisatos, Julie S Biteen, Ali Khademhosseini, Jennifer Doinne, and more!


C&EN and ACS on Campus present: Periodic Table Bingo

3:00-4:00 P.M., San Diego Convention Center, ACS Booth Theater

Join C&EN and ACS on Campus for an unforgettable afternoon of Periodic Table Bingo at the upcoming ACS National Meeting. Celebrate the International Year of the Periodic Table with this interactive game – and win prizes! RSVP now!

Tuesday, August 27th

ACS Sensors Young Investigators

8:00-10:45 A.M., Marriott Marquis San Diego Marina, San Diego Ballroom Salon A


COMSCI: Water for Two Worlds

8:00 A.M.-12:00 P.M.: Technologies for Tomorrow
1:30- 5:00 P.M.: Lighting the Way to Safe Water
Omni San Diego Hotel, Grand Ballroom B


2019 ACS Division of Organic Chemistry Academic Young Investigators Award Symposium

8:20 A.M.-4:00 P.M., San Diego Convention Center, Room 7A


Global Health: Biology and Chemistry of Waterborne Diseases

8:30 A.M., Marriott Marquis San Diego Marina, Marriott Grand Ballroom Section 6


2019 Bioconjugate Chemistry Lectureship Award

9:00 A.M.-12:00 P.M., Manchester Grand Hyatt San Diego, Harbor G
Join Vincent M. Rotello, Editor-in-Chief of Bioconjugate Chemistry, in partnership with the Division of Polymeric Materials Science and Engineering for a symposium honoring Professor Heather D. Maynard – recipient of this year’s Lectureship Award.


Make Your Science Safe

11:00 A.M.-12:00 P.M., San Diego Convention Center, ACS Booth Theater
Watch new ACS safety videos and learn about the ACS safety resources, including the new ACS Chemical Health & Safety journal. Find out how YOU can get involved in growing safety cultures.


Advances in Bioconjugate Materials for Biomedical Applications

1:30-5:00 P.M., Manchester Grand Hyatt San Diego, Harbor G
Hear from Vincent M. Rotello, Editor-in-Chief of Bioconjugate Chemistry, and several journal associate editors at this unique PMSE/POLY supported symposium.


ACS Infectious Diseases Young Investigators Award Symposium

1:00 P.M., Marriott Marquis San Diego Marina, Marriott Grand Ballroom Section 6


2019 Biomacromolecules/Macromolecules Young Investigator Award

1:00-5:00 P.M., Manchester Grand Hyatt San Diego, Coronado D
Join the editors of ACS Macro Letters, Biomacromolecules, and Macromolecules, in partnership with the Division of Polymer Chemistry for a symposium honoring Julien Nicolas and Ilja K. Voets – winners of this year’s Biomacromolecules/Macromolecules Young Investigator Award.


Beyond Chemistry: ACS Publications Bio Journals

1:10-1:50 P.M, San Diego Convention Center Exhibit Hall, ACS Booth Theater


Journal of Agricultural and Food Chemistry 2019 Research Article of the Year Award Lectureship Winners (AGFD): Nutrition, Diet, Functional Foods in Health

1:20 P.M. San Diego Convention Center, Room 32B


PHYS Division Awards, Including The Journal of Physical Chemistry and PHYS Division Lectureship Awards

1:30-5:15 P.M., Marriott Marquis San Diego Marina, Marriott Grand Ballroom Section 13


Langmuir Lectures, Nano Letters Award Lecture, ACS Materials & Interfaces Award Lecture

2:00-5:00 P.M., San Diego Convention Center, Room 5B

Celebrate outstanding researchers in materials and nanoscience: the 2019 Langmuir Lectureship Awards recognize Professor Katsuhiko Ariga and Professor Ayusman Sen, and the ACS Applied Materials & Interfaces Young Investigator Award goes to Professor Jessica Schiffman. This symposium celebrates their achievements and gives you the opportunity to hear more about their research.


Chemical Research in Toxicology Young Investigator Award Symposium

2:00 P.M., Omni San Diego Hotel, Gallery 1

Wednesday, August 28th

AAAS Marion Milligan Mason Award Symposium, Sponsored by ACS Central Science

9:00 A.M.–12:00 P.M., Manchester Grand Hyatt San Diego
Reception will follow immediately after

ACS Publications Editors Discuss How Scientific Publishing Has Changed

Science never stays still for long. The ideas of today will have to make room for the breakthroughs of tomorrow. But just as our understanding of the world evolves, so has the way scientists go about sharing their discoveries. ACS Editors are all accomplished active researchers and over the course of their long careers, they’ve seen a number of significant changes to the process of taking research out of the lab notebook and getting it into a respected journal. In this video, ACS Publications Editors share their thoughts on how scientific publishing has changed since they began their careers.

Some of those changes are usually considered to be positive, such as all the ways that the submission process has become faster and simpler. But some of these changes are more controversial. A reliance on metrics for evaluating journals, papers, and researchers, for example, may have removed some nuance from the publication process. Different researchers may come to different conclusions about these changes, but one thing is certain: There’s no going back.

Watch ACS Editors Discuss How Scientific Publishing Has Changed


The ACS Publications Editors featured in the video are (in order of appearance): Professor Jillian M. Buriak, Editor-in-Chief of Chemistry of Materials; Professor Prashant V. Kamat, Editor-in-Chief of ACS Energy Letters; Professor Luis Liz-Marzán, Associate Editor of ACS Nano; Professor Kai Rossen Editor-in-Chief of Organic Process Research & Development; Professor Cynthia J. Burrows Editor-in-Chief of Accounts of Chemical Research.

In the comments, share your reflection on how scientific publishing has changed during your career.

Hairy Electronic Skin Catches the Breeze

Designing sensors that mimic those in human skin could lead to more realistic prosthetic limbs that can feel a light touch or the warm sun. But no flexible electronic skin so far has included the small feelers that make mammals unique: hair. Now, by placing microscopic polymer hairs on top of graphene, researchers have made a skinlike sensing device that can feel wind and detect its direction and angle. The technology, they say, could lead to wearable sensors that are more sensitive and responsive and to new kinds of soft or winged robots.

An array of 16 graphene sensors on a piece of flexible plastic forms the basis of a new sensor that can map the strength, direction, and angle of wind.

Electronic skin has typically been made of an array of sensors embedded in or printed on a rubbery polymer. Recent innovations include e-skin that can monitor vital signs or can heal itself. Yet most research so far has focused on mimicking skin’s essential ability to sense touch and temperature, which would allow a robotic arm to pick up a cup or know if it’s hot.

Hair enhances the skin’s ability to sense pressure, especially light pressure such as a landing bug or a gentle breeze. Scientists have recently found that bats use hair on their wings to detect airflow and change flight direction in a split second. Artificial skin with hair would more closely mimic the real thing, says Changhyun Pang, a chemical engineer at Sungkyunkwan University. Others have attempted hairy sensors before, but they were complicated to make and mounted on rigid substrates. Such strategies won’t work for soft e-skins or flexible wearable electronics, he says.

Pang and his colleagues made a 4-by-4 array of sensors by spraying a suspension of graphene nanoflakes through a stencil onto a piece of flexible polyethylene. Each sensor is a 4 by 4 mm patch of graphene nanoflakes only 15 µm thick. Applying pressure on the sensors pushes the nanoflakes together, changing the electrical resistance. Using a different stencil, the researchers then top the sensor area with thicker 170 µm graphene nanoflake films that are highly conductive and form a pair of electrodes.

Next comes the hair. The researchers molded a thin poly(dimethylsiloxane) film covered with a forest of microscopic pillars. They placed this on top of one half of the sensor array so that one half is smooth while the other is hairy.

20190408lnp4-sailingrobot.gif

Credit: Changhyun Pang

A robot moves the farthest when air blows perpendicular to its sail. When air blows at a 45° angle, a sensor detects airflow angle and direction, and the sail pivots to face the breeze and move forward.

To test the device, the researchers blew air on it and measured the electrical current from each sensor in the array. The breeze bent the microhairs and put pressure on the graphene sensors, changing their output current. Stronger drafts generated higher current. Researchers calculated the flow’s direction by looking at a map of the sensors’ output; pillars directly facing the wind bent more. To measure the angle of airflow, the researchers measured the difference in the current from the smooth side, which monitors downward force, and the hairy side, which measures force across the array. The hairy sensors can detect an airflow pressure of 0.2 kilopascal—a gentle pressure that our skin can feel. Although previous e-skins have been able to sense pressures below a kilopascal, those devices cannot trace the flow direction and angle.

Finally, as a practical demonstration, the team attached the hairy sensor to a wheeled robot powered by a sail. The sensor detected airflow and rotated the sail, adjusting it to the wind direction so the robot could move forward.

Researchers have made whiskers that can detect surface texture before, says Darren J. Lipomi, a nanoengineer at the University of California, San Diego. But this work is novel because it uses rubbery micropillars to relay the mechanical forces from wind to the graphene sensors in the device, he says, thus mimicking the hair follicle receptors in human skin. Given the simple printing and molding techniques, it should be straightforward to produce practical sensors on a large area, he adds.

This article is reproduced with permission from C&EN (© American Chemical Society). The article was first published on April 08, 2019.