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Alfa Chemistry provides custom services to modify graphene quantum dots (GQDs). GQD provides a way to instill excellent optical, electronic, mechanical and adsorption properties into various platforms. GQDs modified with various functional groups has good potential application prospects in biosensors, biomedicine, solar photovoltaic devices and other fields. We support our customers with practical guidance on GQD modification.
Many early applications of GQD mainly used its inherent luminescence characteristics. As the complexity of the GQD platform increases, it is also necessary to modify and manipulate the inherent chemical composition, increase functionality, impart reactivity, and change optical properties.Various chemical methods have been used to successfully functionalize the GQD surface through covalent and non-covalent means.
Fig 2. Surface modification strategies of Graphene Quantum Dots. (Nekoueian K, et al. 2019)
Considering the relatively abundant carboxylic acid groups decorating the periphery of the GQD, the condensation reaction has always been the preferred method for most chemists to functionalize the material.
The phenolic groups located on the GQD outer surface have been used to form new ester bonds. Other examples have exploited the GQD phenolic groups by reacting with highly active acid chloride or anhydride reagents.
Carboxylic acid groups on GQDs can be converted to acid chlorides using (COCl)2 en route to their desired ester and amide products, respectively.
Fig 3. Two examples of outlining the preparation and use of GQD-acid chloride. (Sweetman M. J, et al. 2019)
Another condensation reaction which has been used to functionalize the surface of GQDs is achieved by reacting 1,2-quinone or 1,2-diols with 1,2-diamines to form diimines.
This reactivity can be exploited by treating GQDs with epoxide functional groups with aqueous ammonia under forced conditions (treatments at 100 and 200°C for 5 and 10 hours, respectively) to obtain amino-modified GQDs.
The high electron density in GQDs, due to their conjugated aromatic scaffold, lends these materials to electrophilic aromatic substitution (EAS) reactions when reacted with an appropriate electrophile.
Graphene quantum dots modification can be used in but not limited to the following fields.
Our experts in chemistry have the right answers and strategies for GQD modification. We will use simulations to design functional target groups, establish structural feature models, and guide the synthesis of new products. If you are interested in our services, please contact us for more detailed information.