team of Pakistani scientists developed fluorescent nanoparticles from spent tea through an eco-friendly procedure. These nanoparticles could act like sensors in various medical applications.
Aumber Abbas – a PhD scholar at the Newcastle University, UK and others from Oxford University UK, made this discovery by converting tea waste into Graphene Quantum Dots (GQDs) to design a highly selective sensor to detect iron in drinking water and Parkinson’s patients.
The tiny particles are made from graphene – an allotrope of Carbon discovered in 2004 – consist of a sheet of carbon atoms that could be collected from a piece of graphite with scotch tape. The discovery of this magic material was awarded the Nobel Prize. Till then, graphene is an ideal material for new explorations in material science, medicine and other fields.
Scientists and engineers around the world are still busy in fine-tuning graphene for desirable results. For instance, in March 2018, Pablo Jarillo-Herrero at the Massachusetts Institute of Technology (MIT) found that when a one-atom-thick sheet of graphene placed on another with slight twist, the material shows super conductivity. Similarly, the quest for fluorescence in GQDs led the team to do some more tweaks.
The team wanted to glow the particles, but graphene has no bandgap or energy gap. Abbas and colleagues however successfully tried another way to solve this problem.
“One of the challenges with graphene is zero bandgap that limits its optical emission and applications in fluorescence field. To this end, I solved this challenge by cutting graphene sheet into small pieces and hence introducing bandgap in it. As a result, small pieces of graphene started fluorescing,” Aumber Abbas told The Express Tribune, adding that our main aim was to develop low cost advanced material, therefore we started from a waste ‘used black tea’.
