Tag Archives: Washington University in St. Louis

Eliminate cold storage for diagnostic tests?

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There’s a nanoparticle coating that could eliminate the need for cold storage and/or refrigeration for diagnostic testing according to a Jan. 4, 2017 news item on Nanowerk,

Many diagnostic tests use antibodies to help confirm a myriad of medical conditions, from Zika infections to heart ailments and even some forms of cancer. Antibodies capture and help detect proteins, enzymes, bacteria and viruses present in injuries and illnesses, and must be kept at a constant low temperature to ensure their viability — often requiring refrigeration powered by electricity. This can make diagnostic testing in underdeveloped countries, disaster or remote areas and even war zones extremely expensive and difficult.

A team of engineers from Washington University in St. Louis and Air Force Research Laboratory have discovered an inexpensive work-around: a protective coating that could completely eliminate the need for cold storage and change the scope of medical diagnostic testing in places where it’s often needed the most.

“In many developing countries, electricity is not guaranteed,” said Srikanth Singamaneni, associate professor of mechanical engineering and materials science in Engineering & Applied Science at Washington University in St. Louis.

“So how do we best get them medical diagnostics? We did not know how to solve this problem previously.”

A Jan. 4, 2016 Washington University in St. Louis news release by Erika Ebsworth-Goold, which originated the news item, describes how previous research helped lead to a solution,

Singamaneni’s team previously used tiny gold nanorods in bio-diagnostic research, measuring changes in their optical properties to quantify protein concentrations in bio-fluids: the higher a concentration, the higher the likelihood of injury or disease.

In this new research, published in Advanced Materials, Singamaneni worked with faculty from Washington University’s School of Medicine and researchers from the Air Force Research Lab to grow metal-organic frameworks (MOFs) around antibodies attached to gold nanorods. The crystalline MOFs formed a protective layer around the antibodies and prevented them from losing activity at elevated temperatures. The protective effect lasted for a week even when the samples were stored at 60°C.

“This technology would allow point-of-care screening for biomarkers of diseases in urban and rural clinic settings where immediate patient follow-up is critical to treatment and wellbeing,” said Dr. Jeremiah J. Morrissey, professor of anesthesiology, Division of Clinical and Translational Research, Washington University School of Medicine and a co-author on the paper.

“On the spot testing eliminates the time lag in sending blood/urine samples to a central lab for testing and in tracking down patients to discuss test results. In addition, it may reduce costs associated with refrigerated shipping and storage.”

The protective MOF layer can be quickly and easily removed from the antibodies with a simple rinse of slightly acidic water, making a diagnostic strip or paper immediately ready to use. Singamaneni says this proof of concept research is now ready to be tested for clinical samples.

“As long as you are using antibodies, you can use this technology,” said Congzhou Wang, a postdoctoral researcher in Singamaneni’s lab and the paper’s lead author. “In bio-diagnostics from here on out, we will no longer need refrigeration.”

“The MOF-based protection of antibodies on sensor surfaces is ideal for preserving biorecognition abilities of sensors that are designed for deployment in the battlefield,” said Dr. Rajesh R. Naik, 711th Human Performance Wing of the Air Force Research Laboratory, Wright-Patterson Air Force Base, and a co-corresponding author of the paper.  “It provides remarkable stability and extremely easy to remove right before use.”

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

Metal-Organic Framework as a Protective Coating for Biodiagnostic Chips by Congzhou Wang, Sirimuvva Tadepalli, Jingyi Luan, Keng-Ku Liu, Jeremiah J. Morrissey, Evan D. Kharasch, Rajesh R. Naik, and Srikanth Singamaneni. Advanced Materials DOI: 10.1002/adma.201604433 Version of Record online: 7 DEC 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

A final observation, there’s at least one other project aimed at eliminating the need for refrigeration in the field of medical applications and that’s the nanopatch, a replacement for syringes used for liquid medications and vaccines (see my Dec. 16, 2016 posting for a description).

Nanoparticles for sustainable ways to grow crops

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An April 29, 2016 news item on Nanowerk celebrates research into food production,

Scientists are working diligently to prepare for the expected increase in global population — and therefore an increased need for food production— in the coming decades. A team of engineers at Washington University in St. Louis has found a sustainable way to boost the growth of a protein-rich bean by improving the way it absorbs much-needed nutrients.

Ramesh Raliya, a research scientist, and Pratim Biswas, the Lucy & Stanley Lopata Professor and chair of the Department of Energy, Environmental & Chemical Engineering, both in the School of Engineering & Applied Science, discovered a way to reduce the use of fertilizer made from rock phosphorus and still see improvements in the growth of food crops by using zinc oxide nanoparticles.

The food under investigation is the mung bean,

Researchers at Washington University in St. Louis hope that nanoparticle technology can help reduce the need for fertilizer, creating a more sustainable way to grow crops such as mung beans. Courtesy: Washington University in St. Louis

Researchers at Washington University in St. Louis hope that nanoparticle technology can help reduce the need for fertilizer, creating a more sustainable way to grow crops such as mung beans. Courtesy: Washington University in St. Louis

An April 28, 2016 Washington University in St. Louis  news release (also on EurekAlert) by Beth Miller, which originated the news item, provides more detail,

The research was published April 7 [2016] in the Journal of Agricultural and Food Chemistry. Raliya said this is the first study to show how to mobilize native phosphorus in the soil using zinc oxide nanoparticles over the life cycle of the plant, from seed to harvest.

Food crops need phosphorus to grow, and farmers are using more and more phosphorus-based fertilizer as they increase crops to feed a growing world population. However, the plants can only use about 42 percent of the phosphorus applied to the soil, so the rest runs off into the water streams, where it grows algae that pollutes our water sources. In addition, nearly 82 percent of the world’s phosphorus is used as fertilizer, but it is a limited supply, Raliya says.

“If farmers use the same amount of phosphorus as they’re using now, the world’s supply will be depleted in about 80 years,” Raliya said. “Now is the time for the world to learn how to use phosphorus in a more sustainable manner.”

Raliya and his collaborators, including Jagadish Chandra Tarafdar at the Central Arid Zone Research Institute in Jodhpur, India, created zinc oxide nanoparticles from a fungus around the plant’s root that helps the plant mobilize and take up the nutrients in the soil. Zinc also is an essential nutrient for plants because it interacts with three enzymes that mobilize the complex form of phosphorus in the soil into a form that plants can absorb.

“Due to climate change, the daily temperature and rainfall amounts have changed,” Raliya said. “When they changed, the microflora in the soil are also changed, and once those are depleted, the soil phosphorus can’t mobilize the phosphorus, so the farmer applies more. Our goal is to increase the activity of the enzymes by several-fold, so we can mobilize the native phosphorus several-fold.”

When Raliya and the team applied the zinc nanoparticles to the leaves of the mung bean plant, it increased the uptake of the phosphorus by nearly 11 percent and the activity of the three enzymes by 84 percent to 108 percent. That leads to a lesser need to add phosphorus on the soil, Raliya said.

“When the enzyme activity increases, you don’t need to apply the external phosphorus, because it’s already in the soil, but not in an available form for the plant to uptake,” he said. “When we apply these nanoparticles, it mobilizes the complex form of phosphorus to an available form.”

The mung bean is a legume grown mainly in China, southeast Asia and India, where 60 percent of the population is vegetarian and relies on plant-based protein sources. The bean is adaptable to a variety of climate conditions and is very affordable for people to grow.

Raliya said 45 percent of the worldwide phosphorus use for agriculture takes place in India and China. Much of the phosphorus supply in developing countries is imported from the United States and Morocco-based rock phosphate mines.

“We hope that this method of using zinc oxide nanoparticles can be deployed in developing countries where farmers are using a lot of phosphorus,” Raliya said.

“These countries are dependent on the U.S. to export phosphorus to them, but in the future, the U.S. may have to help supply food, as well. If this crop can grow in a more sustainable manner, it will be helpful for everyone.”

“This is a broader effort under way at the nexus of food, energy and water,” Biswas said. “Nanoparticle technology enabled by aerosol science helps develop innovative solutions to address this global challenge problem that we face today.”

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

Enhancing the Mobilization of Native Phosphorus in the Mung Bean Rhizosphere Using ZnO Nanoparticles Synthesized by Soil Fungi by Ramesh Raliya, Jagadish Chandra Tarafdar, and Pratim Biswas. J. Agric. Food Chem., 2016, 64 (16), pp 3111–3118 DOI: 10.1021/acs.jafc.5b05224 Publication Date (Web): April 07, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Tomatoes and some nano-sized nutrients

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While zinc is a metal, it’s also a nutrient vital to plants as a Nov. 5, 2015 news item on ScienceDaily notes,

With the world population expected to reach 9 billion by 2050, engineers and scientists are looking for ways to meet the increasing demand for food without also increasing the strain on natural resources, such as water and energy — an initiative known as the food-water-energy nexus.

Ramesh Raliya, PhD, a postdoctoral researcher, and Pratim Biswas, PhD, the Lucy & Stanley Lopata Professor and chair of the Department of Energy, Environmental & Chemical Engineering, both at the School of Engineering & Applied Science at Washington University in St. Louis, are addressing this issue by using nanoparticles to boost the nutrient content and growth of tomato plants. Taking a clue from their work with solar cells, the team found that by using zinc oxide and titanium dioxide nanoparticles, the tomato plants better absorbed light and minerals, and the fruit had higher antioxidant content.

A Nov. 5, 2015 Washington University in St. Louis news release by Beth Miller (also on EurekAlert but dated Nov. 6, 2015), which originated the news item, describes the work in more detail,

“When a plant grows, it signals the soil that it needs nutrients,” Biswas says. “The nutrient it needs is not in a form that the plant can take right away, so it secretes enzymes, which react with the soil and trigger bacterial microbes to turn the nutrients into a form that the plant can use. We’re trying to aid this pathway by adding nanoparticles.”

Zinc is an essential nutrient for plants, helps other enzymes function properly and is an ingredient in conventional fertilizer. Titanium is not an essential nutrient for plants, Raliya says, but boosts light absorption by increasing chlorophyll content in the leaves and promotes photosynthesis, properties Biswas’ lab discovered while creating solar cells.

The team used a very fine spray using novel aerosolization techniques to directly deposit the nanoparticles on the leaves of the plants for maximum uptake.

“We found that our aerosol technique resulted in much greater uptake of nutrients by the plant in comparison to application of the nanoparticles to soil,” Raliya says. “A plant can only uptake about 20 percent of the nutrients applied through soil, with the remainder either forming stable complexes with soil constituents or being washed away with water, causing runoff. In both of the latter cases, the nutrients are unavailable to plants.”

Overall, plants treated with the nanoparticles via aerosol routes produced nearly 82 percent (by weight) more fruit than untreated plants. In addition, the tomatoes from treated plant showed an increase in lycopene, an antioxidant linked to reduced risk of cancer, heart disease and age-related eye disorders, of between 80 percent and 113 percent.

Previous studies by other researchers have shown that increasing the use of nanotechnology in agriculture in densely populated countries such as India and China has made an impact on reducing malnutrition and child mortality. These tomatoes will help address malnutrition, Raliya says, because they allow people to get more nutrients from tomatoes than those conventionally grown.

In the study, published online last month in the journal Metallomics, the team found that the nanoparticles in the plants and the tomatoes were well below the USDA limit and considerably lower than what is used in conventional fertilizer. However, they still have to be cautious and select the best concentration of nanoparticles to use for maximum benefit, Biswas says.

Raliya and the rest of the team are now working to develop a new formulation of nanonutrients that includes all 17 elements required by plants.

“In 100 years, there will be more cities and less farmland, but we will need more food,” Raliya says. “At the same time, water will be limited because of climate change. We need an efficient methodology and a controlled environment in which plants can grow.”

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

Mechanistic evaluation of translocation and physiological impact of titanium dioxide and zinc oxide nanoparticles on the tomato (Solanum lycopersicum L.) plant by Ramesh Raliya, Remya Nair, Sanmathi Chavalmane, Wei-Ning Wang and Pratim Biswas. Metallomics, 2015, Advance Article DOI: 10.1039/C5MT00168D First published online 08 Oct 2015

I believe this article is behind a paywall.

Solar cells and copper sprouts

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First, Washington University in St. Louis (WUSTL; located in Missouri, US) announced a discovery about solar cells, then, the university announced a commitment to increase solar output by Fall 2014. Whether these two announcements are linked by some larger policy or strategy is not clear to me but it’s certainly an interesting confluence of events.

An April 26, 2014 news item on Azonano describes the researchers’ discovery,

By looking at a piece of material in cross section, Washington University in St. Louis engineer Parag Banerjee, PhD, and his team discovered how copper sprouts grass-like nanowires that could one day be made into solar cells.

Banerjee, assistant professor of materials science and an expert in working with nanomaterials, Fei Wu, graduate research assistant, and Yoon Myung, PhD, a postdoctoral research associate, also took a step toward making solar cells and more cost-effective.

An April 21, 2014 WUSTL news release by Beth Miller, which originated the news item, describes the research in some detail,

Banerjee and his team worked with copper foil, a simple material similar to household aluminum foil. When most metals are heated, they form a thick metal oxide film. However, a few metals, such as copper, iron and zinc, grow grass-like structures known as nanowires, which are long, cylindrical structures a few hundred nanometers wide by many microns tall. They set out to determine how the nanowires grow.

“Other researchers look at these wires from the top down,” Banerjee says. “We wanted to do something different, so we broke our sample and looked at it from the side view to see if we got different information, and we did.”

…

The team used Raman spectroscopy, a technique that uses light from a laser beam to interact with molecular vibrations or other movements. They found an underlying thick film made up of two different copper oxides (CuO and Cu2O) that had narrow, vertical columns of grains running through them. In between these columns, they found grain boundaries that acted as arteries through which the copper from the underlying layer was being pushed through when heat was applied, creating the nanowires.

“We’re now playing with this ionic transport mechanism, turning it on and off and seeing if we can get some different forms of wires,” says Banerjee, who runs the Laboratory for Emerging and Applied Nanomaterials (L.E.A.N.).

Like solar cells, the nanowires are single crystal in structure, or a continuous piece of material with no grain boundaries, Banerjee says.

“If we could take these and study some of the basic optical and electronic properties, we could potentially make solar cells,” he says. “In terms of optical properties, copper oxides are well-positioned to become a solar energy harvesting material.”

This work may be useful in other applications according to the news release,

The find may also benefit other engineers who want to use single crystal oxides in scientific research. Manufacturing single crystal Cu2O for research is very expensive, Banerjee says, costing up to about $1,500 for one crystal.

“But if you can live with this form that’s a long wire instead of a small crystal, you can really use it to study basic scientific phenomena,” Banerjee says.

Banerjee’s team also is looking for other uses for the nanowires, including acting as a semiconductor between two materials, as a photocatalyst, a photovoltaic or an electrode for splitting water.

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

Unravelling transient phases during thermal oxidation of copper for dense CuO nanowire growth by Fei Wu, Yoon Myunga and Parag Banerjee.  CrystEngComm, 2014,16, 3264-3267. DOI: 10.1039/C4CE00275J First published online 26 Feb 2014

This article is behind a paywall.

Shortly after the research announcement, WUSTL made this ‘solar’ announcement via an April 29, 2014 news release by Neil Schoenherr,

Washington University in St. Louis is moving forward with a bold and impactful plan to increase solar output on all campuses by 1,150 percent over current levels by this fall. The project demonstrates the university’s commitment to sustainable operations and to reducing its environmental impact in the St. Louis region and beyond.

This spring and early summer, the university will add a total of 379 kilowatts (kw) of solar on university-owned property throughout the region. Prior to this installation, the university had 33 kw that were installed as demonstration projects.

I suspect the two announcements reflect synchronicity or, perhaps, my tendency to see and develop patterns.