Non-invasive formaldehyde sensor

About Non-invasive formaldehyde sensor:

• Materials used: Tin oxide-reduced graphene oxide composite (rGO- SnO2).
• While reduced graphene oxide (rGO) has been used to detect various toxic gases and VOCs, Tin Oxide (SnO2) has been extensively investigated for formaldehyde detection in pristine form and by incorporating it with various compounds, including graphene, due to its high stability and high sensitivity toward low concentrations of formaldehyde.
• Process: The Graphene oxide (GO) was processed through wet chemical approach and tin oxide-reduced graphene oxide composite (rGO- SnO2) was synthesised by hydrothermal route followed by calcination of the obtained product.
• They found that the sensor made of tin oxide decorated with reduced graphene oxide effectively sensed formaldehyde vapour at room temperature.
• The sensor shows long-term stability with a low detection limit.
• A new low-cost sensor made of metal oxide nanoparticles reduced graphene oxide composite can detect formalin adulteration in fishes at room temperature in a non-invasive way.
• The research for this is supported by DST-PURSE (Promotion of University Research and Scientific Excellence).
• Existing sensors:
  • Commercial formalin sensors for fish are primarily electrochemical-based or colorimetric-based. Electrochemical sensors are extensively used but are expensive.
  • The calorimetric sensors are less expensive. But both methods are invasive in nature.
  • Issue: Low-level detection and selective detection are two major issues with these sensors.
• Significance of new sensor:
  • The development of 2D materials-based gas sensors has created a new avenue of effective detection of toxic vapours at room temperature.
  • These sensors have the potential to detect the formalin evaporated from adulterated food products.

What is Formaldehyde?

• It is a colourless, pungent gas that is used in a variety of industrial processes, including as a preservative in some foods, commonly in fish in developing countries.