• 文献标题:   Distinctive sensing nanotool for free and nanoencapsulated quercetin discrimination based on S,N co-doped graphene dots
  • 文献类型:   Article
  • 作  者:   MONTES C, VILLAMAYOR N, VILLASENOR MJ, RIOS A
  • 作者关键词:   fluorescent quenching discrimination, codoped graphene quantum dot, nanometrology, nanoemulsion synthesi, quercetin, nutraceutical
  • 出版物名称:   ANALYTICA CHIMICA ACTA
  • ISSN:   0003-2670 EI 1873-4324
  • 通讯作者地址:  
  • 被引频次:   0
  • DOI:   10.1016/j.aca.2022.340406 EA SEP 2022
  • 出版年:   2022

▎ 摘  要

A selective and sensitive fluorescent nanoprobe (sulfur and nitrogen co-doped graphene quantum dots, S,N-GQDs) was designed for both detection and discrimination between free and quercetin-loaded nanoemulsion in food samples of diverse nature. Quercetin nanoemulsions (Q-NEs) were synthesized by a phase inversion temperature (PIT) procedure, while S,N-GQDs were synthesized using a bottom-up methodology by means of simple hydrothermal treatment of citric acid and cysteamine. Both synthetized nanomaterials (analyte and fluorescent probe), were carefully characterized through advanced spectroscopic and high-resolution micro-scopic techniques. It was observed that fluorescence intensity of S,N-GQDs could be markedly and distinctively quenched by the addition of both quercetin forms through inner filter effect (IFE) mechanisms, exhibiting static quenching events for free quercetin and Q-NEs but with a characteristic 13 nm red-shift spectra in presence of Q-NEs. Linear dynamic ranges between 0.05 and 10 mg L-1 and 0.025-70 mg L-1, with detection limits of 17 and 8 mu g L-1 were revealed for free and nanoquercetin, respectively. After nanostructural and physic-chemical opti-mization, the discrimination strategy was metrologically validated and applied to nutraceutical supplements containing nanoencapsulated quercetin and on diverse free quercetin products such as onion peels and dietary supplements. Accuracy and reliability were proved by means of a statistical comparison with the results obtained by a mu HPLC-DAD method (paired Student's t-test at 95% confidence level). The method provides the exciting prospect of analyzing new designed nanoencapsulated bioactives without altering their native nanostructure, as well as being able to accomplish the challenge to distinguish between both forms of quercetin.