Tag Archives: Institute of Bioengineering and Nanotechnology (IBN)

Killing bacteria on contact with dragonfly-inspired nanocoating

Scientists in Singapore were inspired by dragonflies and cicadas according to a March 28, 2018 news item on Nanowerk (Note: A link has been removed),

Studies have shown that the wings of dragonflies and cicadas prevent bacterial growth due to their natural structure. The surfaces of their wings are covered in nanopillars making them look like a bed of nails. When bacteria come into contact with these surfaces, their cell membranes get ripped apart immediately and they are killed. This inspired researchers from the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR to invent an anti-bacterial nano coating for disinfecting frequently touched surfaces such as door handles, tables and lift buttons.

This technology will prove particularly useful in creating bacteria-free surfaces in places like hospitals and clinics, where sterilization is important to help control the spread of infections. Their new research was recently published in the journal Small (“ZnO Nanopillar Coated Surfaces with Substrate-Dependent Superbactericidal Property”)

Image 1: Zinc oxide nanopillars that looked like a bed of nails can kill a broad range of germs when used as a coating on frequently-touched surfaces. Courtesy: A*STAR

A March 28, 2018 Agency for Science Technology and Research (A*STAR) press release, which originated the news item, describes the work further,

80% of common infections are spread by hands, according to the B.C. [province of Canada] Centre for Disease Control1. Disinfecting commonly touched surfaces helps to reduce the spread of harmful germs by our hands, but would require manual and repeated disinfection because germs grow rapidly. Current disinfectants may also contain chemicals like triclosan which are not recognized as safe and effective 2, and may lead to bacterial resistance and environmental contamination if used extensively.

“There is an urgent need for a better way to disinfect surfaces without causing bacterial resistance or harm to the environment. This will help us to prevent the transmission of infectious diseases from contact with surfaces,” said IBN Executive Director Professor Jackie Y. Ying.

To tackle this problem, a team of researchers led by IBN Group Leader Dr Yugen Zhang created a novel nano coating that can spontaneously kill bacteria upon contact. Inspired by studies on dragonflies and cicadas, the IBN scientists grew nanopilllars of zinc oxide, a compound known for its anti-bacterial and non-toxic properties. The zinc oxide nanopillars can kill a broad range of germs like E. coli and S. aureus that are commonly transmitted from surface contact.

Tests on ceramic, glass, titanium and zinc surfaces showed that the coating effectively killed up to 99.9% of germs found on the surfaces. As the bacteria are killed mechanically rather than chemically, the use of the nano coating would not contribute to environmental pollution. Also, the bacteria will not be able to develop resistance as they are completely destroyed when their cell walls are pierced by the nanopillars upon contact.

Further studies revealed that the nano coating demonstrated the best bacteria killing power when it is applied on zinc surfaces, compared with other surfaces. This is because the zinc oxide nanopillars catalyzed the release of superoxides (or reactive oxygen species), which could even kill nearby free floating bacteria that were not in direct contact with the surface. This super bacteria killing power from the combination of nanopillars and zinc broadens the scope of applications of the coating beyond hard surfaces.

Subsequently, the researchers studied the effect of placing a piece of zinc that had been coated with zinc oxide nanopillars into water containing E. coli. All the bacteria were killed, suggesting that this material could potentially be used for water purification.

Dr Zhang said, “Our nano coating is designed to disinfect surfaces in a novel yet practical way. This study demonstrated that our coating can effectively kill germs on different types of surfaces, and also in water. We were also able to achieve super bacteria killing power when the coating was used on zinc surfaces because of its dual mechanism of action. We hope to use this technology to create bacteria-free surfaces in a safe, inexpensive and effective manner, especially in places where germs tend to accumulate.”

IBN has recently received a grant from the National Research Foundation, Prime Minister’s Office, Singapore, under its Competitive Research Programme to further develop this coating technology in collaboration with Tan Tock Seng Hospital for commercial application over the next 5 years.

1 B.C. Centre for Disease Control

2 U.S. Food & Drug Administration

(I wasn’t expecting to see a reference to my home province [BC Centre for Disease Control].) Back to the usual, here’s a link to and a citation for the paper,

ZnO Nanopillar Coated Surfaces with Substrate‐Dependent Superbactericidal Property by Guangshun Yi, Yuan Yuan, Xiukai Li, Yugen Zhang. Small https://doi.org/10.1002/smll.201703159 First published: 22 February 2018

This paper is behind a paywall.

One final comment, this research reminds me of research into simulating shark skin because that too has bacteria-killing nanostructures. My latest about the sharkskin research is a Sept, 18, 2014 posting.

Oil spill cleanups with supergelators

Researchers in Singapore have proposed a new technology for cleaning up oil spills, according to a June 17, 2016 news item on Nanowerk,

Large-scale oil spills, where hundreds of tons of petroleum products are accidentally released into the oceans, not only have devastating effects on the environment, but have significant socio-economic impact as well [1].

Current techniques of cleaning up oil spills are not very efficient and may even cause further pollution or damage to the environment. These methods, which include the use of toxic detergent-like compounds called dispersants or burning of the oil slick, result in incomplete removal of the oil. The oil molecules remain in the water over long periods and may even be spread over a larger area as they are carried by wind and waves. Further, burning can only be applied to fresh oil slicks of at least 3 millimeters thick, and this process would also cause secondary environmental pollution.

In a bid to improve the technology utilized by cleanup crews to manage and contain such large spills, researchers from the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR [located in Singapore] have invented a smart oil-scavenging material or supergelators that could help clean up oil spills efficiently and rapidly to prevent secondary pollution.

These supergelators are derived from highly soluble small organic molecules, which instantly self-assemble into nanofibers to form a 3D net that traps the oil molecules so that they can be removed easily from the surface of the water.

A June 17, 2016 IBN A*STAR media release, which originated the news item, provides more detail,

“Marine oil spills have a disastrous impact on the environment and marine life, and result in an enormous economic burden on society. Our rapid-acting supergelators offer an effective cleanup solution that can help to contain the severe environmental damage and impact of such incidents in the future,” said IBN Executive Director Professor Jackie Y. Ying.

Motivated by the urgent need for a more effective oil spill control solution, the IBN researchers developed new compounds that dissolve easily in environmentally friendly solvents and gel rapidly upon contact with oil. The supergelator molecules arrange themselves into a 3D network, entangling the oil molecules into clumps that can then be easily skimmed off the water’s surface.

“The most interesting and useful characteristic of our molecules is their ability to stack themselves on top of each other. These stacked columns allow our researchers to create and test different molecular constructions, while finding the best structure that will yield the desired properties,” said IBN Team Leader and Principal Research Scientist Dr Huaqiang Zeng. (Animation: Click to see how the supergelators stack themselves into columns.)

IBN’s supergelators have been tested on various types of weathered and unweathered crude oil in seawater, and have been found to be effective in solidifying all of them. The supergelators take only minutes to solidify the oil at room temperature for easy removal from water. In addition, tests carried out by the research team showed that the supergelator was not toxic to human cells, as well as zebrafish embryos and larvae. The researchers believe that these qualities would make the supergelators suitable for use in large oil spill areas.

The Institute is looking for industrial partners to further develop its technology for commercial use. [emphasis mine]

Video: Click to watch the supergelators in action

  1. The well documented BP Gulf of Mexico oil well accident in 2010 was a catastrophe on an unprecedented scale, with damages amounting to hundreds of billions of dollars. Its wide-ranging effects on the marine ecosystem, as well as the fishing and tourism industries, can still be felt six years on.

Here’s a link to and a citation for the paper,

Instant Room-Temperature Gelation of Crude Oil by Chiral Organogelators by Changliang Ren, Grace Hwee Boon Ng, Hong Wu, Kiat-Hwa Chan, Jie Shen, Cathleen Teh, Jackie Y. Ying, and Huaqiang Zeng. Chem. Mater., 2016, 28 (11), pp 4001–4008 DOI: 10.1021/acs.chemmater.6b01367 Publication Date (Web): May 10, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

I have featured other nanotechnology-enabled oil spill cleanup solutions here. One of the more recent pieces is my Dec. 7, 2015 post about boron nitride sponges. The search terms: ‘oil spill’ and ‘oil spill cleanup’ will help you unearth more.

There have been some promising possibilities and I hope one day these clean up technologies will be brought to market.

Hydro-Québec, lithium-ion batteries, and silicate-based nanoboxes

Hydro-Québec (Canada) is making a bit of a splash these days (this is the third mention within less than a week) on my blog, if nowhere else. The latest development was announced in a Feb. 24, 2015 news item on Nanowerk (Note: A link has been removed),

Researchers from Singapore’s Institute of Bioengineering and Nanotechnology (IBN) of A*STAR and Quebec’s IREQ (Hydro-Québec’s research institute) have synthesized silicate-based nanoboxes that could more than double the energy capacity of lithium-ion batteries as compared to conventional phosphate-based cathodes (“Synthesis of Phase-Pure Li2MnSiO4@C Porous Nanoboxes for High-Capacity Li-Ion Battery Cathodes”). This breakthrough could hold the key to longer-lasting rechargeable batteries for electric vehicles and mobile devices.

A Feb. 24, 2015 Hydro-Québec press release (also on Canadian News Wire), which originated the news item, describe the research and the relationship between the two institutions,

“IBN researchers have successfully achieved simultaneous control of the phase purity and nanostructure of Li2MnSiO4 for the first time,” said Professor Jackie Y. Ying, IBN Executive Director. “This novel synthetic approach would allow us to move closer to attaining the ultrahigh theoretical capacity of silicate-based cathodes for battery applications.”

“We are delighted to collaborate with IBN on this project. IBN’s expertise in synthetic chemistry and nanotechnology allows us to explore new synthetic approaches and nanostructure design to achieve complex materials that pave the way for breakthroughs in battery technology, especially regarding transportation electrification,” said Dr. Karim Zaghib, Director – Energy Storage and Conservation at Hydro-Québec.

Lithium-ion batteries are widely used to power many electronic devices, including smart phones, medical devices and electric vehicles. Their high energy density, excellent durability and lightness make them a popular choice for energy storage. Due to a growing demand for long-lasting, rechargeable lithium-ion batteries for various applications, significant efforts have been devoted to improving the capacity of these batteries. In particular, there is great interest in developing new compounds that may increase energy storage capacity, stability and lifespan compared to conventional lithium phosphate batteries.

The five-year research collaboration between IBN and Hydro-Québec was established in 2011. The researchers plan to further enhance their new cathode materials to create high-capacity lithium-ion batteries for commercialization.

Here’s a link to and a citation for the paper,

Synthesis of phase-pure Li2MnSiO4@C porous nanoboxes for high-capacity Li-ion battery cathodes by Xian-Feng Yang, Jin-Hua Yang, Karim Zaghib, Michel L. Trudeau, and Jackie Y. Ying. Nano Energy Volume 12, March 2015, Pages 305–313 doi:10.1016/j.nanoen.2014.12.021

This paper is behind a paywall.

Here are my two most recent mentions of Hydro-Québec and lithium-ion batteries (both Grafoid and NanoXplore have deals with Hydro-Québec),

Investment in graphene (Grafoid), the Canadian government, and a 2015 federal election (Feb. 23, 2015)

NanoXplore: graphene and graphite in Québec (Canada) (Feb. 20, 2015)