# Bottom-up microwave transformation of molecules to carbon dots for detection and encryption applications

## TL;DR

Researchers created carbon dots using a microwave method that can detect harmful substances in water and be used for secure information transfer.

## Contribution

A microwave-assisted method to produce multifunctional carbon dots for contaminant detection and secure information encryption.

## Key findings

- Carbon dots detected Cr6+ and doxycycline with low detection limits of 0.14 and 0.09 µM.
- Carbon dots showed stability and sensitivity in various environmental conditions.
- Carbon dots were used for secure information transport via fluorescent ink and anti-counterfeiting features.

## Abstract

The development of low-cost, stable, and effective fluorescent materials for detecting carcinogenic water contaminants and antibiotic drugs is a significant step toward protecting the environment and public health. In this work, we have prepared CDs using simple precursors, tartaric acid and di-aminopropane, via a facile, fast, one-step microwave-assisted method in 4 minutes. The as-prepared CDs were thoroughly investigated using sophisticated analytical techniques, including UV-Vis, PL lifetime, HR-TEM, and XRD. The exciting fluorescent excitation-dependent and independent character was revealed by photoluminescence, XPS, and FT-IR measurements, and it was found that CDs were made with a uniform core and an electron-rich surface functional group. Also, the prepared CDs exhibit greater stability in various environmental conditions. Furthermore, the core fluorescent character of CDs was effectively employed to detect Cr6+ and doxycycline, with lower detection limits of 0.14 and 0.09 µM, among the various metal cation and antibiotic groups. Additionally, it retains its sensitivity in the presence of multiple co-existing metal cations and antibiotics individually. In addition to environmental protection, we have utilized CDs for the secure transport of information via fluorescent ink and anti-counterfeiting security features. This present work displays the multifunctional ability of CDs, that can serve as a potential sensor for toxic metal ions and antibiotics in water based environments and also an excellent information encryptor for secure information transportation.

Multifunctional carbon dots from tartaric acid and diaminopropane prepared using a microwave assisted method have the potential to serve as a dual contaminant sensor and invisible security ink for secure information transmission.