Tag Archives: University of Hyderabad

Taking spectroscopy to a new dimension with silver nanoparticles

This latest move towards better detection at the nanoscale comes from India (from a January 2, 2018 news item on ScienceDaily),

As medicine and pharmacology investigate nanoscale processes, it has become increasingly important to identify and characterize different molecules. Raman spectroscopy, a technique that leverages the scattering of laser light to identify molecules, has a limited capacity to detect molecules in diluted samples because of low signal yield.

A team of researchers from the University of Hyderabad in India has improved molecular detection at low concentration levels by arranging nanoparticles on nanowires to enhance Raman spectroscopy. Surface-enhanced Raman spectroscopy (SERS) uses electromagnetic fields to improve Raman scattering and boost sensitivity in standard dyes such as R6G by more than one billionfold.

Here’s an image illustrating the work,

Caption: Detection of a low concentration analyte molecule using silicon nanowires decorated with silver nanoparticles and surface enhanced Raman scattering measurements. Credit: V.S. Vendamani

A January 2, 2017 American Institute of Physics press release on EurekAlert, which originated the news item, explains further,

The team decorated vertically aligned silicon nanowires with varying densities of silver nanoparticles, utilizing and enhancing the structure’s 3-D shape. Their results, published in the Journal of Applied Physics, from AIP [American Institute of Physics] Publishing, show that their device was able to enhance the Raman signals for cytosine protein and ammonium perchlorate by a factor of 100,000.

“The beauty is that we can improve the density of these nanowires using simple chemistry,” said Soma Venugopal Rao, one of the paper’s authors. “If you have a large density of nanowires, you can put more silver nanoparticles into the substrate and can increase the sensitivity of the substrate.”

Applying the necessary nanostructures to SERS devices remains a challenge for the field. Building these structures in three dimensions with silicon nanowires has garnered attention for their higher surface area and superior performance, but silicon nanowires are still expensive to produce.

Instead, the team was able to find a cheaper way to make silicon nanowires and used a technique called electroless etching to make a wide range of nanowires. They “decorated” these wires with silver nanoparticles with variable and controlled densities, which increased the nanowires’ surface area.

“Optimizing these vertically aligned structures took a lot of time in the beginning,” said Nageswara Rao, another of the paper’s authors. “We increased the surface area and to do this we needed to change the aspect ratio.”

After optimizing their system to detect Rhodamine dye on a nanomolar level, these new substrates the team built enhanced Raman sensitivity by a factor of 10,000 to 100,000. The substrates detected concentrations of cytosine, a nucleotide found in DNA, and ammonium perchlorate, a molecule with potential for detecting explosives, in as dilute concentrations as 50 and 10 micromolar, respectively.

The results have given the team reason to believe that it might soon be possible to detect compounds in concentrations on the scale of nanomolar or even picomolar, Nageswara Rao said. The team’s work has opened several avenues for future research, from experimenting with different nanoparticles such as gold, increasing the sharpness of the nanowires or testing these devices across several types of molecules.

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

Three-dimensional hybrid silicon nanostructures for surface enhanced Raman spectroscopy based molecular detection featured by V. S. Vendamani, S. V. S. Nageswara Rao, S. Venugopal Rao, D. Kanjilal, and A. P. Pathak. Journal of Applied Physics 123, 014301 (2018); Published Online: January 2018 https://doi.org/10.1063/1.5000994

This paper is open access.

Kenya and a draft nanotechnology policy

I don’t often stumble across information about Kenya’s nanotechnology efforts (my last was in a Sept. 1, 2011 posting) but I’m going include my latest find here even though I can’t track down the original source for the information. From an April 29, 2015 news item on SpyGhana (original source: Xinhua News Agency,  official press agency of the People’s Republic of China),

The Kenyan government will soon adopt a comprehensive policy to promote use of nanotechnology in diverse fields like medicine, agriculture, manufacturing and environment.

“Nanotechnology as a science promises more for less. The competitive edge for Kenya as a developing nation lies in robust investments in this technology,” Njeri Wamae, chairman of National Commission for Science, Technology and Innovation (NACOSTI), said in Nairobi.

Nanotechnology is relatively new in Kenya though the government has prioritized its development through research, training and setting up of supportive infrastructure.

Wamae noted that enactment of a nanotechnology policy will position Kenya as a hub for emerging technologies that would revolutionalize key sectors of the economy.

Policy briefs from Kenya’s scientific research body indicates that globally, nanotechnology was incorporated into manufacturing goods worth over 30 billion U.S. dollars in 2005.

The briefs added that nanotechnology related business was worth 2.6 trillion dollars by 2015. Kenya has borrowed best practices from industrialized countries and emerging economies to develop nanotechnology.

Professor Erastus Gatebe, an official at Kenya Industrial Research and Development Institute (KIRDI), noted that China and India offers vital lessons on harnessing nanotechnology to propel industrial growth.

This draft policy seems to be the outcome of a number of initiatives including Nanotechnologies for Development in India, Kenya and the Netherlands: Towards a Framework for Democratic Governance of Risks in Developing Countries, WOTRO (2010 – 2014) from the African Technology Policy Studies (ATPS) Network,

The ATPS has secured funding for a new Integrated Program (IP) on “Nanotechnologies for Development in India, Kenya and the Netherlands: Towards a Framework for Democratic Governance of Risks in Developing Countries, January 2010 – 2014, in liaison with partners in Europe and India. This IP which is led by Prof. Wiebe Bijker of the University of Maastricht, the Netherlands addresses the inevitable risks and benefits associated with emerging technologies, such as nanotechnology through a triangulation of PhD and Post-Doctoral positions drawn from Africa (2), India (1) and the Netherlands (2) based at the University of Maastricht but address core areas of the nanotechnology governance in Africa, India and the Netherlands. The program will be coordinated by Prof. Wiebe Bijker, the University of Maastricht, in the Netherlands; with the University of Hyderabad, India; the ATPS and the University of Nairobi, Kenya as partners.

Nanotechnology events and discussions played in important role in Kenya’s 2013 National Science, Technology and Innovation (ST&I) Week by Daphne Molewa (on the South African Agency for Science and Technology Advancement [SAASTA] website),

The National Science, Technology and Innovation (ST&I) Week, organised by the Ministry of Higher Education, Science and Technology, is a major event on the annual calendar of the Kenyan Government.

The theme for 2013, “Science, Technology and Innovation for the realisation of Kenya’s Vision 2030 and beyond” is aligned with the national vision to transform Kenya into a newly industrialised, middle-income country providing a high-quality life to all its citizens in a safe and secure environment by the year 2030. pemphasis mine]

Nanotechnology, the science of the future

SAASTA representatives Mthuthuzeli Zamxaka and Sizwe Khoza were invited to participate in this year’s festival in Nairobi [Kenya] on behalf of the Nanotechnology Public Engagement Programme (NPEP).

Zamxaka delivered a stirring presentation titled Nanotechnology Public Engagement: The Case of South Africa. He introduced the topic of nanotechnology, focusing on engagement, outreach and awareness. …

Zamxaka touched on a number of nanotechnologies that are currently being applied, such as the research conducted by the Johns Hopkins University in Maryland on biodegradable nano-sized particles that can easily slip through the body’s sticky and viscous mucus secretions to deliver a sustained-release medication cargo. It is believed that these nanoparticles, which degrade over time into harmless components, could one day carry life-saving drugs to patients suffering from dozens of health conditions, including diseases of the eye, lung, gut or female reproductive tract.

For anyone interested , look here for Kenya’s Vision 2030. Harkening back to the first news item and the mention of NACOSTI, Kenya’s National Commission for Science, Technology and Innovation, it can be found here.

Nanotechnology in the developing world/global south

Sometimes it’s called the ‘developing world’, sometimes it’s called the ‘global south’ and there have been other names before these. In any event, the organization, Nanotechnology for Development (Nano-dev) has released a policy brief about nanotechnology and emerging economies (?). Before discussing the brief, I have found a little information on the organization. From the Nano-dev home page,

Nanotechnology for development is a research project that aims at understanding how nanotechnology can contribute to development. By investigating way people deal with nanotechnology in Kenya, India and the Netherlands, the project will flesh out appropriate ways for governing nanotechnology for development.

Nanotechnology is a label for technologies at the nano-scale, roughly between 1 and 100 nanometers. This is extremely small. By comparison, the diameter of one human hair is about 60,000 nanometers. At this scale materials acquire all sorts of new characteristics that can be used in a wide range of novel applications. This potentially includes cheaper and more efficient technologies that can benefit the world’s poor, such as cheap water filters, efficient solar powered electricity, and portable diagnostic tests.

The four team members on the Nano-dev project are (from the Project Team page):

Pankaj Sekhsaria’s project seeks to understand the cultures of innovation in nanotechnology research in India, particularly in laboratories. He has a Bachelors Degree in Mechanical Engineering from Pune University in India and a MA in Mass Communication from the Jamia Milia Islamia in New Delhi, India.

Trust Saidi’s research is on travelling nanotechnologies. He studied BSc in Geography and Environmental Studies at Zimbabwe Open University, BSc Honours in Geography at University of Zimbabwe, MSc in Public Policy and Human Development at Maastricht Graduate School of Governance, Maastricht University.

Charity Urama’s project investigates the role of knowledge brokerage in nanotechnology for development. She obtained her BSc Botany from the faculty of Biological Sciences, University of Nigeria, Nsukka and MSc from the school of Biological and Environmental Sciences, Faculty of Life sciences, University of Aberdeen (UK).

Koen Beumer focuses on the democratic risk governance of nanotechnologies for development. Koen Beumer studied Arts and Culture (BA) and Cultures of Arts, Science and Technology (MPhil, cum laude) at Maastricht University.

According to the April 4, 2012 news item on Nanowerk about the brief,

The key message of the policy brief is that nanotechnology can have both positive and negative consequences for countries in the global South. These should be pro-actively dealt with.

The positive consequences of nanotechnology include direct benefits in the form of solutions to the problems of the poor and indirect benefits in the form of economic growth. The negative consequences of nanotechnology include direct risks to human health and the environment and indirect risks such as a deepening of the global divide. Core challenges to harnessing nanotechnology for development include risk governance, cultures of innovation, knowledge brokerage and travelling technology.

What I found particularly interesting in the policy brief is the analysis of nanotechnology efforts in countries that are not usually mentioned  (from the policy brief),

There are large differences amongst countries in the global South. Some countries, like India, Egypt, Brazil and South Africa, have invested substantial sums of money through dedicated programs. Often these are large countries with emerging economies. Dedicated programs and strategies have been generated with strong political support.

In other countries in the global South things look different. Several African countries, like Nigeria, Kenya, Uganda and Zimbabwe have expressed their interest in nanotechnologies and some activities can indeed be observed. But generally this activity does not exceed the level of individual researchers and incidental funding. [p. 3]

In addition to the usual concerns expressed over human health, they mention this risk,

Furthermore, properties at the nano-scale may be used to imitate the properties of rare minerals, thus affecting the export rates of their main producers, usually countries in the global South. Nanotechnologies may thus have reverse effects on material demands and consequently on the export of raw materials by countries in the global South (Schummer 2007). [p. 3]

Interesting thought that nanotechnology research could pose a risk to the economic welfare of countries that rely on the export of raw materials. Canada, anyone? If you think about it, all the excitement over nanocellulose doesn’t have to be an economic boon for ‘forestry-based’ countries. If cellulose is the most abundant polymer on earth what’s stop other countries from using their own nanocellulose. After all, Brazilian researchers are working on nanocellulose fibres derived from pineapples and bananas (my Mar. 28, 2011 and June 16, 2011 postings).

One final thing from the April 4, 2012 news item on Nanowerk,

The NANO-DEV project is partnership of three research institutes led by Maastricht University, the Netherlands. Besides Maastricht University, it includes the University of Hyderabad (India) and the African Technology Policy Studies Network (Kenya).