Multifunctional N,S-doped and methionine functionalized carbon dots for on-off-on Fe3+ and ascorbic acid sensing, cell imaging, and fluorescent ink applying

Zheng Yang; Tiantian Xu; Shaobing Zhang; Hui Li; Yali Ji; Xiaodan Jia; Jianli Li

doi:10.1007/s12274-022-5107-7

Multifunctional N,S-doped and methionine functionalized carbon dots for on-off-on Fe³⁺ and ascorbic acid sensing, cell imaging, and fluorescent ink applying

Nano Res. 2023;16(4):5401-5411. doi: 10.1007/s12274-022-5107-7. Epub 2022 Nov 9.

Authors

Zheng Yang^{1

2

3}, Tiantian Xu², Shaobing Zhang², Hui Li^{1

2}, Yali Ji¹, Xiaodan Jia^{2

3}, Jianli Li¹

Affiliations

¹ Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an, 710127 China.
² College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an, 710054 China.
³ Key Laboratory of Coal Resources Exploration and Comprehensive Utilization, Ministry of Land and Resources, Xi'an, 710012 China.

Abstract

Fluorescent carbon dots (CDs) have been identified as potential nanosensors and attracted tremendous research interests in wide areas including anti-counterfeiting, environmental and biological sensing and imaging in considering of the attractive optical properties. In this work, we present a CDs based fluorescent sensor from polyvinylpyrrolidone, citric acid, and methionine as precursors by hydrothermal approach. The selective quantifying of Fe³⁺ and ascorbic acid (AA) are based on the fluorescent on-off-on process, in which the fluorescent quenching is induced by the coordination of the Fe³⁺ on the surface of the CDs, while the fluorescence recovery is mainly attributed to redox reaction between Fe³⁺ and AA, breaking the coordination and bringing the fluorescence back. Inspired by the good water solubility and biocompatibility, significant photostability, superior photobleaching resistance as well as high selectivity, sensitivity, and interference immunity, which are constructed mainly from the N,S-doping and methionine surface functionalization, the CDs have not only been employed as fluorescence ink in multiple anti-counterfeiting printing and confidential document writing or transmitting, but also been developed as promising fluorescence sensors in solution and solid by CDs doped test strips and hydrogels for effectively monitoring and removing of Fe³⁺ and AA in environmental aqueous solution. The CDs have been also implemented as effective diagnostic candidates for imaging and tracking of Fe³⁺ and AA in living cells, accelerating the understanding of their function and importance in related biological processes for the prevention and treatment specific diseases.

Electronic supplementary material: Supplementary material (fluorescence spectra: UV and Xe irradiation, TG, thermo stability, ionic strength, relationship between fluorescence responses at different concentrations of Fe³⁺ and AA, reaction time-dependent fluorescent responses; XPS spectra of CDs + Fe³⁺ and Fe³⁺@CDs + AA; structural characterization; equations about fluorescence lifetime, quantum yield and LOD; comparison of the CDs for the detection of Fe³⁺ and AA with reported methods; detection of Fe³⁺ and AA in real samples; absorption of Fe³⁺ in environmental samples and MTT assay results) is available in the online version of this article at 10.1007/s12274-022-5107-7.

Keywords: Fe3+; ascorbic acid; carbon dots; fluorescent ink; fluorescent sensors; message encryption.