MUMBAI, India, Sept. 14 -- Intellectual Property India has published a patent application (202641100511 A) filed by Saveetha Institute Of Medical And Technical Sciences on August 20, 2026, for Highly Fluorecent, Ultra - Small Nitrogen Doped Carbon Quantum Dots (cqds) From Cellulose.
Inventors include Indra Neel Pulidindi; Deepak Nallaswamy Veeraiyan; and Tharikka S.
The application for the patent was published on September 11, 2026, under issue no. 37/2026.
Abstract: Abstract The invention deals with the green and sustainable process for the production of nitrogen enriched (both doped and surface functionalized) carbon quantum dots (N-CQDs) using the highly recalcitrant material, namely, the microcrystalline cellulose (MCC) as the carbon feedstock. Another unique feature of the invention in the use of a green nitrogen precursor which is of low thermal stability, namely, ammonium carbonate, that decomposes at around 60 C and generating both the needed alkaline environment and nitrogen source (ammonia) for the doping of the carbon nanodot structure with nitrogen. Moreover, the synthesis of carbon nanodot structure from MCC is via the isosaccharinic acid intermediate. It is known that under alkaline environment cellulose degrades to smaller molecules via isosaccharinic acid intermediate. The isosaccharinic acid intermediate is carbonized in alkaline aqueous medium in the hydrothermal process conducted at 200 °C and for a duration of 5 h. Highly hydrophilic, uniformly dispersed, agglomeration free, nitrogen enriched carbon quantum dots are produced in a single step without any prior pretreatment of the highly recalcitrant MCC. The conversion of the MCC in the typical process is nearly 39.6 wt.% to N-CQDs. The unreacted MCC is easily separated from the product stream, namely, N-CQDs via centrifugation. The supernatant is separated from the precipitate in the centrifugation tube via decantation and the decanted aqueous product is free from any traces of the reactant. The product purity is tested from HR-TEM, UV-Vis, and FT-IR studies. The N-CQDs are highly fluorescent with down- conversion as well as excitation dependent emission. The N-CQDs are ultra-small and homogeneously distributed though out without any traces of agglomeration with high stabiliity in the nano-regime as revealed from the HR-TEM analysis. The N-CQDs showed the d-spacing value of 0.253 nm typical of the graphene layers bound to Frenkel type structural defects. Such defective structures endow the N-CQDs with highly active reaction cites for catalytic application. Moreover, the material is highly doped with nitrogen, typically with pyridine like nitrogen, C=N bonds, indicative of their potential as molecular models for photoluminescence analogous to that of the quinine sulphate. The N-CQDS are highly surface functionalized with functionalities like amide, ether and hydroxyl groups contributing to their extensive hydrophilicity enlarging their domain in biomedical applications such as antimicrobial agents, and bio-imaging agents apart from being potential biosensors. Thus a green and sustainable production process for the synthesis of ultra-small, highly fluorescent, extensively nitrogen enriched carbon quantum dots is invented with application in catalysis, and biomedicine and electronics
Disclaimer: Curated by HT Syndication.
