In situ one-pot synthesis of graphitic carbon nitride quantum dots and its 2,2,6,6-tetramethyl(piperidin-1-yl)oxyl derivatives as fluorescent nanosensors for ascorbic acid

Ojodomo J. Achadu, Tebello Nyokong

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)

Abstract

Graphitic carbon nitride quantum dots (gCNQDs) when alone or containing embedded 4-amino-2,2,6,6-tetramethyl(piperidin-1-yl)oxyl) (4-AT) (gCNQDs-4-AT(embedded)) were synthesized via low temperature in situ one-pot process from diaminomaleonitrile (DAMN). The blue emission of both gCNQDs and gCNQDs-4-AT were excitation wavelength–dependent with very high fluorescence quantum yields of 43 and 51%, respectively. Further, the gCNQDs were covalently linked to 4-AT via an amide bond to give (gCNQDs-4-AT (linked)). gCNQDs were also non-covalently linked to 2,2,6,6-etramethyl(piperidin-1-yl)oxyl (TEMPO, not containing amino groups) derivatized zinc phthalocyanine (ZnPc) to form gCNQDs-TEMPO-ZnPc(π-π). The TEMPO-derivatized gCNQDs (gCNQDs-4-AT(embedded)), gCNQDs-4-AT(linked), or gCNQDs-TEMPO-ZnPc(π-π) were found to be highly sensitive and selective fluorescent probes for ascorbic acid (AA) detection with limits of detection (LOD) in the nanomolar range. Hence, 4-AT (or TEMPO) functionality introduced into the gCNQDs (or ZnPc) afforded the derivation of selective and sensitive AA probes. Real samples were evaluated by the designed probes and satisfactory recoveries further confirmed the analytical applicability of the gCNQDs-based probes.

Original languageEnglish
Pages (from-to)113-126
Number of pages14
JournalAnalytica Chimica Acta
Volume991
DOIs
Publication statusPublished - 18 Oct 2017

Bibliographical note

Funding Information:
This work was supported by the Department of Science and Technology (DST) and National Research Foundation (NRF), South Africa through DST/NRF South African Research Chairs Initiative for Professor of Medicinal Chemistry and Nanotechnology (UID 62620) as well as Rhodes University/DST Centre for Nanotechnology Innovation, Rhodes University, South Africa.

Funding Information:
This work was supported by the Department of Science and Technology (DST) and National Research Foundation (NRF), South Africa through DST/NRF South African Research Chairs Initiative for Professor of Medicinal Chemistry and Nanotechnology (UID 62620) as well as Rhodes University / DST Centre for Nanotechnology Innovation, Rhodes University, South Africa . Appendix A

Publisher Copyright:
© 2017 Elsevier B.V.

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