On-site monitoring of L-adrenaline neurotransmitter in biological samples by chitosan oligosaccharide derived carbon dots

• Novel Chitosan Oligosaccharide (COL) derived carbon dots (CDs) by hydrothermal method . • The synthesized COL-CDs was well characterized by UV–Vis, Fluorescence, XRD , Raman and HR-TEM techniques. • The COL-CDs act as a fluorescent probe for the sensing of L-Adrenaline by fluorescence On-Off strategy. • The reagent free paper based kit was prepared using COL-CDs for the on-site monitoring of L-Adrenaline. Carbon quantum dots (CDs) are fascinating fluorescent nanomaterial for spectrofluorimetry sensor applications, owing to the fact of its strong chemical stability, high quantum yield and high photostability. At this instance, we have developed the fluorescent sensing technique to detect the L-adrenaline (L-Adr) by nitrogen-doped carbon quantum dots as a sensing probe. The nitrogen-doped carbon dots was synthesized using chitosan oligosaccharide by hydrothermal method . The synthesized chitosan oligosaccharide derived CDs (COL-CDs) exhibits blue fluorescence under UV light and the size of the carbon quantum dots is 3.39 ± 0.08 nm calculated from HR-TEM image. The hormone called L-Adr found in the human body is crucial for controlling visceral processes. Utilizing the process of photo-induced electron transfer (PET), the previously mentioned COL-CDs have applied to sense the L-Adr. The sensing mechanism have explained clearly using Rehm-Weller equation by calculating ΔG. Tap water, blood serum, urine and adrenaline drug samples employed as real sample for the sensing L-Adr. A reagent free paper-based kit established for the purpose of on-site monitoring L-Adr. The smartphone’s colour picker software used to measure the RGB intensity from the paper-based kit.