Research Highlights

doi:10.1038/nindia.2017.154 Published online 20 December 2017

Grape seeds help make glowing quantum dots

Researchers have synthesised light-emitting graphene quantum dots using grape seed extracts. This is an eco-friendly way to make such quantum dots, which are potentially useful for making versatile sensing and imaging probes1.

Commercially available dyes used for sensing and imaging purposes easily break down when exposed to light. Besides, most of them unleash toxic effects on the cells.

In search of a biocompatible agent, scientists from the Indian Institute of Technology Bombay, led by Rohit Srivastava and Mukeshchand Thakur, produced powdered graphene quantum dots by heating and drying grape seed extracts in a domestic microwave oven.  

When incubated with different types of cells, the quantum dots entered the cells and then moved from cytoplasm to nucleus within eight hours. Unlike existing dyes, which easily disintegrate, the quantum dots remained stable inside the nucleus for a long period, suggesting its potential as a nucleus-labelling agent and a drug carrier.  

The colour of the quantum dots became darker when pH levels changed from acidic to basic, indicating their pH-sensing potential. Cells containing quantum dots emitted stable red light that could be exploited to develop biosensors for detecting specific biomarkers inside the cells.  

The quantum dots also aided cell proliferation – a property essential for healing wounds.

“Currently, we are trying to develop next-generation wound-healing formulations by combining the quantum dots with specific pharmaceutical ointments,” says Mukesh Kumar Kumawat, the lead author of the study.


References

1. Kumawat, M. K. et al. Graphene quantum dots for cell proliferation, nucleus imaging, and photoluminescent sensing applications. Sci. Rep. 7, 15858 (2017)