ABSTRACT
Utilization of waste is becoming a good option from which numerous useful components can be extracted or synthesized. In this chapter one of such application will be discussed. Citrus limon peels, one of such kind of waste from which a good source of many bioactive and organic compounds can be extracted. Carbon dots are the nanomaterials which size lies below 10 nm, which can be synthesized from many natural and chemical sources. These carbon dots are rich in many properties like fluorescence, photostability, etc which can be utilized in many fields like sensing, bioimaging. So, basically in this chapter synthesis of carbon dots form low-cost raw product, methods of synthesis, and utilization of the same in the sensing purposes of ion like Fe3+ in water will be discussed. Also, discussion will be extended to prepare some pH-based paper by the utilization of the same for sensing of pH in both acidic and alkaline medium which can be visually distinguished.
