Context: Recently, the Centre for Nano and Soft Matter Sciences (CeNS) has developed a compact solid-state sensor to detect the heavy metal ions in water.
About Compact solid-state sensor 

• It is a compact solid-state portable device which can help on-site detection in remote areas.
• Heavy metal ions such as lead, mercury and cadmium pose severe potential threats to living beings as they can easily be accumulated in the body and cannot be detoxified by any chemical or biological processes.
• The health hazards associated with heavy metal ions in water demands the development of efficient and portable sensors for rapid onsite detection of these ions.
• The sensor film was prepared by forming a composite between manganese doped zinc sulfide quantum dots and reduced graphene oxide on a glass substrate.
• The quantum dots are water-soluble and have high photoluminescence (~ 30 %) quantum yield, making them suitable for luminescence-based sensing.
• The quantum dots can be excited with handheld UV light of 254 nm, thus making it a portable device even to remote areas.
• If a drop of water containing heavy metal ions such as mercury, lead, cadmium, etc. is added to the composite film, the emission of the film quenches within seconds.

Why do we need such Sensor?

• Heavy metal ions such as lead, mercury and cadmium pose severe potential threats to living beings as they can easily be accumulated in the body and cannot be detoxified by any chemical or biological processes.
• The health hazards associated with heavy metal ions in water demands the development of efficient and portable sensors for rapid onsite detection of these ions.
• Hence, there is an urge to develop visual sensors, which can effectively detect heavy metal ions rapidly (within seconds) under ambient conditions.

About Centre for Nano and Soft Matter Sciences

• It is an autonomous research institute under the Department of Science and Technology (DST), Government of India.
• DST provides core support to the Centre in the form of a grant-in-aid for conducting basic and applied research in nano and soft matter sciences.
• CeNS is located at Jalahalli, Bengaluru.
• It is being mentored by Nano-Mission of the Government of India.

Origin of CeNS

• The Centre was established in 1991 by an eminent liquid crystal scientist, Prof. S. Chandrasekhar, FRS.
• It was then known as Centre for Liquid Crystal Research.
• In 1995, it became an autonomous institute under the Department of Electronics (DOE), Government of India.In 2003, was brought under DST.
• Subsequently in the year 2010, the name was changed to Centre for Soft Matter Research.
• Recently in 2014, the Centre has further widened the scope of research activities to embrace nanoscience and technology and is now known as Centre for Nano and Soft Matter Sciences (CeNS).

Functional Areas of CeNS

• The Centre is engaged in materials research at all relevant length scales.
• Specifically, the current activities are focussed on a variety of metal and semiconductor nanostructures, liquid crystals, gels, membranes and hybrid materials.
• It has close interactions with many Institutions and Industry, in India and abroad.

About Nano Mission

• It was launched in 2007 as an umbrella capacity-building programme by the Government of India.
• It is being implemented by the Department of Science and Technology.

Its Objectives are as follows

• Basic research promotion.
• Infrastructure development.
• Nano applications and technology development.
• Human Resource development.
• International collaborations.

By this, India has been able to rank amongst the top 5 countries in the world for Scientific Publications in Nanoscience & Technology due to the efforts led by the Nano Mission.

The Nano Mission has established national dialogues to promote R&D in the development of standards for nanotechnology and for laying down a National Regulatory Framework Road-Map for Nanotechnology (NRFR-Nanotech).