 Our drinking water has to go through disinfection process to remove the pathogens. Unfortunately, it also produces disinfection byproducts linked with certain cancer formation, low breast weight and other negative health impacts. So we have been working on synthesizing carbon dots as water quality sensors for some years. We have transformed human hair into carbon nanodots sensitive to chloroform, a small organic molecule that is very difficult to detect usually, and they are fluorescent. And these functional groups interact with the chemical species in water, and these interactions induce signal change in fluorescence as the indicator for the water quality. We have reached three molecules of chloroform per billion water molecules, and usually people could only reach PPM, and PPV is another three orders of magnitudes more sensitive. That is extraordinary. So the carbon dots allows us to develop the real-time sensor technologies for sensing disinfection byproducts to be used in real time and in line. Hair is a very good bio waste. It's light, it's stable, it's rich in protein, rich in carbon, and nitrogen. That makes it a perfect precursor for nitrogen-doped carbon dots synthesis.