Nano-geo Tracers for Understanding Groundwater Flow Dynamics and Contaminants Migration

Since the use of conventional tracers has got some demerits in terms of processibility, toxicity, system alteration, and detectability, it is the need of the hour to introduce some alternate tracer that is devoid of these drawbacks.  Colloidal water-dispersible nanoparticles have unique physical properties. They are heavily used in applications such as drug delivery and bio labeling. The properties that complement such applications include easy detection, controlled diffusion, chemical inertness, and non-toxic nature.

Proposed Applications : Ground Water Exploration, Management and Monitoring of contaminants

This technology works on the principle of fluorescence spectroscopy. Fluorescence occurs when a molecule absorbs light photons from the uv.-visible light spectrum, known as excitation, and then rapidly emits light photons as it returns to its ground state. Fluorimetry characterizes the relationship between absorbed and emitted photons at specified wavelengths. It is a precise quantitative analytical technique that is inexpensive and easily measured

The CQD's were normally synthesized through supercritical reactor process of organic salt of single carbon source, Citric Acid (CA) with the surface modifier polymer Poly sodium 4-styrene sulfonate (PSS). Attachment of PSS on CQD surface makes PSS-CQD powder easily dispersible in aqueous suspension. The citric acid served as the carbon source, while PSS provided stabilization, dispersion in water and control over the particle size. Carbon Quantum Dots are proven as nontoxic and very much environmental friendly the toxicity test was done at IAS-PSG college, Coimbatore, and found as nontoxic.