Carbon dots: A futuristic solution for sustainably managing aquatic environment?

Source: The post is based on the article “Carbon dots: A futuristic solution for sustainably managing aquatic environment?” published in DTE on 3^rd October 2022.

What is the News?

According to scientists, modern technology like nanomaterials or carbon dots (CD) might be the solution to environmental issues like water pollution.

About carbon dots (CD)

CDs are one of the youngest members of the carbon nanomaterial family. They were discovered in 2004 and have an average diameter of less than 10 nanometres.

The dots show continuous and broad absorption spectra, intense fluorescent activity, excellent photostability and highly tunable photoluminescence.

How carbon dots (CD) are formed?

“Top-down” method: This approach converts large carbon structures into quantum-sized carbon dots by laser ablation, arc discharge, and chemical or electrochemical oxidation.

“Bottom-up” method: CDs are produced from carbonising small molecule precursors by pyrolysis, carbonisation, hydrothermal processes or microwave-assisted synthesis.

Note: CDs have also been produced from water hyacinth waste.

What are the advantages of carbon dots (CD)?

-CDs have garnered the attention of researchers mainly due to their convenient availability from both organic and inorganic materials.

-CDs have the potential to be used instead of quantum dots, which are more toxic and less biocompatible.

-CDs possess remarkable optical properties, which differ peculiarly based on the precursor used for synthesis.

-CDs are inexpensive, highly biocompatible, and environment-friendly.

What are the potential applications of carbon dots (CD)?

Pollutant Sensing: CDs are electron donors and acceptors. So they are becoming more popular as candidates in applications like sensing and bioimaging.

They are widely used as a fluorescent nanoprobe for pollutant detection because of their high fluorescence emission. They also enable the detection of pollutants by changing colour.

Note: Organic pollutants in polluted water can act as electron and hole-transferring agents, while carbon dots act as photosensitiser. 

Contaminant Adsorption: CDs can provide many surface adsorption sites due to their small size and large specific surface area.

Water Treatment: CDs contribute rich oxygen-containing moiety on their surface and are favourable for water solubility. Further, they are also promising nano-fillers in fabricating thin-film nanocomposite membranes. So, CDs can be used for water treatment.

For instance, CDs obtained from grass carp successfully detected mercury ions in lake water

Pollutant Degradation: The technology can also be useful for pollutant degradation by providing a cutting-edge approach for next-generation photocatalysis.

For instance, thio-urea and citric acid-based carbon dots were used for the degradation of harmful dyes.

Antimicrobial benefits: CDs in contact with the bacteria cell under visible or natural light could efficiently generate reactive oxygen species. This can damage Deoxyribonucleic Acid (DNA) or Ribonucleic Acid (RNA), causing bacteria death.