Quantification of neomycin in rubella vaccine by off/on metal ion mediated photoluminescence from functionalized graphene quantum dots

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2019-09, Vol.220, p.117139, Article 117139
• Main Authors: Pinto, Igor Araújo, Toloza, Carlos A.T., Almeida, Joseany M.S., da Silva, Andrea R., Larrude, Dunieskys G., Aucélio, Ricardo Q.
• Format: Article
• Language: English
• Subjects: Fe3+ mediation; Functionalized graphene quantum dots; Neomycin sulfate; Photoluminescence; Rubella vaccine
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2019.117139

The determination of neomycin sulfate was made using photoluminescent amino-functionalized graphene quantum dots (obtained from hydro-exfoliation of a mixture of citric acid and glutathione). From the several ions tested, Fe3+ was the best mediator to enable an off/on photoluminescence effect used for quantification. The mediation of Fe3+ was found to be crucial as it is responsible for the photoluminescence quenching effect, due to the interaction with quantum dots surface, also having large affinity towards neomycin that removes Fe3+ from the surface of GQDs, consequently, promoting restoration of the original nanomaterial photoluminescence. Such signal restoration was proportional to the neomycin sulfate concentration added. The linearized analytical response covered three orders of magnitude (10−7 to 10−5 mol L−1). The proposed method is an alternative to those requiring labor-intensive procedures for chemical the derivatization of neomycin (due to the lack of chromophore groups in aminoglycosides). The method was successfully tested in the analysis of rubella vaccine containing trace residues of neomycin and in pharmaceutical compositions containing neomycin sulfate after solid phase extraction using an aminoglycoside imprinted polymer to improve selectivity in determinations. [Display omitted] •Interaction between quantum dots and aminoglycosides mediated by metal ions are studied.•Neomycin restores photoluminescence from the graphene quantum dots.•The functionalized graphene quantum dot probe to detect down to 74 nmol L−1 of neomycin.•Solid phase extraction using an aminoglycoside selective phase ensured selectivity.•A method to determine neomycin in rubella vaccine using a photoluminescence off/on probe is described.