title: Sulfur and nitrogen co-doped carbon dots sensors for nitric oxide fluorescence quantification.
abstract: Microwave synthetized sulfur and nitrogen co-doped carbon dots responded selectively to nitric oxide (NO) at pH 7. Citric acid, urea and sodium thiosulfate in the proportion of 1:1:3 were used respectively as carbon, nitrogen and sulfur sources in the carbon dots microwave synthesis. For this synthesis, the three compounds were diluted in 15 mL of water and exposed for 5 min to a microwave radiation of 700 W. It is observed that the main factor contributing to the increased sensitivity and selectivity response to NO at pH 7 is the sodium thiosulfate used as sulfur source. A linear response range from 1 to 25 μM with a sensitivity of 16 μM-1and a detection limit of 0.3 μM were obtained. The NO quantification capability was assessed in standard and in fortified serum solutions.
authors.affiliation: Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Faculdade de Farmácia da Universidade de Coimbra, Pólo das Ciências da Saúde, 3000-548 Coimbra, Portugal; Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Departamento de Geociências, Ambiente e Ordenamento do Território, Faculdade de Ciências da Universidade do Porto, R. Campo Alegre 687, 4169-007 Porto, Portugal.
authors.forename: Eliana F C
authors.initials: EF
authors.lastname: Simões
authors.affiliation: Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Faculdade de Farmácia da Universidade de Coimbra, Pólo das Ciências da Saúde, 3000-548 Coimbra, Portugal. Electronic address: jleitao@ff.uc.pt.
authors.forename: João M M
authors.initials: JM
authors.lastname: Leitão
authors.affiliation: Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Departamento de Geociências, Ambiente e Ordenamento do Território, Faculdade de Ciências da Universidade do Porto, R. Campo Alegre 687, 4169-007 Porto, Portugal.
authors.forename: Joaquim C G
authors.initials: JC
authors.lastname: Esteves da Silva
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*; D009569:Nitric Oxide / Q000032:analysis* / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013455:Sulfur / Q000737:chemistry*
chemical_list: D009569:Nitric Oxide; D013455:Sulfur; D002244:Carbon; D009584:Nitrogen
keywords: Carbon dots; Citric acid; Fluorescence quenching; Nitric oxide; Sodium thiosulfate; Urea; pH 7