Fe3+-Sensitive Carbon Dots for Detection of Fe3+ in Aqueous Solution and Intracellular Imaging of Fe3+ Inside Fungal Cells

Abstract

In this article, the Fe 3+-sensitive carbon dots were obtained by means of a microwave-assisted method using glutamic acid and ethylenediamine as reactants. The carbon dots exhibited selective response to Fe 3+ ions in aqueous solution with a turn-off mode, and a good linear relationship was found between (F 0-F)/F 0 and the concentration of Fe 3+ in the range of 8-80 µM. As a result, the as-synthesized carbon dots can be developed as a fluorescent chemosensor for Fe 3+ in aqueous solution. Moreover, the carbon dots can be applied as a fluorescent agent for fungal bioimaging since the fungal cells stained by the carbon dots were brightly illuminated on a confocal microscopy excited at 405 nm. Furthermore, an increase in the concentration of intracellular Fe 3+ could result in fluorescence quenching of the carbon dots in the fungal cells when incubated in the Tris-HCl buffer solution containing Fe 3+. However, due to EDTA might hinder Fe(III) to enter the fungal cells, incubation in Fe(III)-EDTA complex solution exerted negligible effect on the fluorescence of fungal cells labeled by the carbon dots. Therefore, the carbon dots can serve as a potential probe for intracellular imaging of Fe 3+ inside fungal cells.

Biomass-Based Polymer Nanoparticles With Aggregation-Induced Fluorescence Emission for Cell Imaging and Detection of Fe3+ Ions

“…The limitation of detection (LOD) was estimated to be 0.17 μM based on the signal-to-noise ratio (SNR) of 3 (3σ/m, σ is the standard deviation of the blank signal ( n = 3) and m is the slope of the linear fit). This value is well below the maximum allowable level of Fe 3+ in drinking water set by the World Health Organization (5.36 μM), Moreover, the method of detecting Fe 3+ based on carbon dots in this article was comparable or even better than that in other previous reports (Shen et al, 2017 ; Chen et al, 2019 ; Arumugham et al, 2020 ). The results indicated that LBE owned a good application prospect in the detection of trace Fe 3+ due to the low LOD of Fe 3+ (Wang et al, 2018 ).…”

Insights and Perspectives Regarding Nanostructured Fluorescent Materials toward Tackling COVID-19 and Future Pandemics

“…These CDs have shown a high sensitivity to Hg 2+ ions with an LOD of 0.23 nM. In another study, Chen et al 178 reported the synthesis of CDs from l -glutamic acid using a microwave-assisted pyrolysis approach. These CDs showed an excellent selectivity and sensitivity to Fe 3+ ions in both solution medium and inside fungal cells (LOD = 3.8 μM).…”

Lignin-based smart materials: a roadmap to processing and synthesis for current and future applications

“…Later, Shi et al reported a facile synthesis of LCQDs by the introduction of secondary amine groups into lignin through Mannich and Michael addition reactions followed by carbonization, milling and filtration. 89 The resulting LCQDs showed an excellent performance for the detection of iron ions (Fe 3+ ) in a wide range of concentrations (1-100 nM) and lower detection limits (8 nM) compared to those of other CQDs based on foodstuff precursors as is the case of citric acid (0.3 mM) 102 or red lentils (0.10 mM) 103 among others 104,105 (Fig. 4a and b).…”