Researchers have synthesised fluorescent carbon dots from rosy periwinkle plant leaves that can be used as nanotags for detecting and killing cancer cells1.

Current cancer-detecting techniques use quantum dots that use toxic metals. They are expensive to produce and easily break down when exposed to light.

To develop a safe way to detect cancer cells, scientists from the Indian Institute of Technology, Roorkee, heated a solution of finely chopped periwinkle plant leaves under controlled conditions and then cooled it down to room temperature. This process yielded nanosized carbon dots.

When incubated with specific mice cells, the carbon dots entered the cells. These cells showed enhanced fluorescence, indicating that the dots reached inside the cells. The dots selectively bound to microtubules, filamentous intracellular structures that support cell division and help transport various molecules inside the cells.

The dots destabilised the structure of the microtubules, converting them into fragments that accumulated inside the cells. This, in turn, inhibited the normal activity of the microtubules arresting cell division – a key property that makes the dots potentially useful for stopping the proliferation of cancer cells.

This is an economical and green way to produce fluorescent carbon dots from the leaves of a common medicinal plant, says lead researcher Gopinath Packirisamy.