IIT Bombay’s sensor detects zinc in sweat, soil in real-time

 

In news:

• A highly sensitive sensor that can detect real-time the presence of zinc over a wide concentration range — 0.1-500 ppm — has been fabricated by researchers at the Indian Institute of Technology (IIT) Bombay.

 

Important facts:

• The electrochemical sensor can be used for detecting zinc in the soil even in the presence of other elements and also at minute levels as seen in human sweat.
• Accurate determination of zinc in soil samples will help in soil-nutrient assessment and prevent overuse of fertilisers while measuring zinc in sweat samples can help signal early onset of muscular fatigue.
•  It can be used as a noninvasive point-of-care sensor. The sensor requires only few microliters of analyte, thus making it possible to detect zinc in sweat samples.
• The researchers are working on developing a read-out device to use the sensor in collaboration with Electrical Engineering Department at IIT Bombay. This project is funded by the Nanomission program of DST India and is intended to complement the soil-health card program of the Indian government.
• The researchers are already working on developing similar sensors for other plant nutrients such as potassium, nitride, phosphate and sodium.

 

Nanomission program Nano Technology is a knowledge-intensive and “enabling technology” which is expected to influence a wide range of products and processes with far-reaching implications for national economy and development. The Government of India, in May 2007, has approved the launch of a Mission on Nano Science and Technology (Nano Mission) with an allocation of Rs. 1000 crore for 5 years. The Department of Science and Technology is the nodal agency for implementing the Nano Mission. Capacity-building in this upcoming area of research will be of utmost importance for the Nano Mission so that India emerges as a global knowledge-hub in this field. For this, research on fundamental aspects of Nano Science and training of large number of manpower will receive prime attention. The Nano Mission will strive for development of products and processes for national development, especially in areas of national relevance like safe drinking water, materials development, sensors development, drug delivery, etc.  For this, it will forge linkages between educational and research institutions and industry and promote Public Private Partnerships. The Nano Mission has been structured in a fashion so as to achieve synergy between the national research efforts of various agencies in Nano Science and Technology and launch new programmes in a concerted fashion.

 

 

Mechanically sturdy

• The sensor is mechanically sturdy and so the signal response remains unaffected even when the sensor is bent 180 degrees.
• The sensor can also be employed over 4-7 pH range, indicating its usefulness for both sweat-based physiological sensing and soil-nutrient assessment.
• The sensor has one working electrode and a reference electrode. These electrodes are made of cellulose fibre coated with carbon nanotubes. The working electrode is coated with a polymeric ion-receptor (tetrakis aminophenyl porphyrin) that binds specifically to zinc.
• A fixed voltage is applied to the electrodes and there is an increase in current when zinc binds to the porphyrin receptor on carbon nanotubes. The amount of increase in current depends on the concentration of zinc that binds to the electrode.

 

Porphyrin receptor:

• The porphyrin receptor in mixed with polyvinyl chloride (PVC) and then coated on carbon nanotubes.
• Using the PVC matrix ensures uniformity in terms of porphyrin coverage on carbon nanotubes.
• The porphyrin receptor has a cage-like structure with a void in the centre. “The size and charge of the void matches perfectly with zinc. The matching size makes it possible for zinc to bind to porphyrin and the charge allows the interaction between the two.

 

 

Additional Information:

Zinc Deficiency

• Zinc supports cell function, helping an estimated 100 enzymes perform their duties. It plays additional roles in the body, including:
  • boosting immune function,
  • helping cells divide,
  • maintaining the sense of smell and taste,
  • promoting wound healing,
  • Zinc also supports a person's growth and development. As such, it is an essential mineral for pregnant women as well as growing children.

• Human body does not store zinc, which means getting enough of the mineral from food is important in preventing a deficiency.
• Inadequate zinc intake can have serious health consequences, particularly for young children, who are more susceptible to contracting malaria, diarrhoeal diseases and pneumonia, when suffering from zinc deficiency.
• The presence of zinc plays a critical role in human immune systems.
• National grain fortification programmes, increased dietary diversity, bio-fortified crops, and reduced carbon dioxide emissions could make a difference to slow or reverse the course.

 

 

Source)

https://www.thehindu.com/todays-paper/tp-features/tp-sci-tech-and-agri/iit-bombays-sensor-detects-zinc-in-sweat-soil-in-real-time/article29748096.ece