Natural Nitrogen-Doped Carbon Dots Obtained from Hydrothermal Carbonization of Chebulic Myrobalan and Their Sensing Ability toward Heavy Metal Ions

Abstract

Chebulic Myrobalan is the main ingredient in the Ayurvedic formulation Triphala, which is used for kidney and liver dysfunctions. Herein, natural nitrogen-doped carbon dots (NN-CDs) were prepared from the hydrothermal carbonization of Chebulic Myrobalan and were demonstrated to sense heavy metal ions in an aqueous medium. Briefly, the NN-CDs were developed from Chebulic Myrobalan by a single-step hydrothermal carbonization approach under a mild temperature (200 °C) without any capping and passivation agents. They were then thoroughly characterized to confirm their structural and optical properties. The resulting NN-CDs had small particles (average diameter: 2.5 ± 0.5 nm) with a narrow size distribution (1–4 nm) and a relatable degree of graphitization. They possessed bright and durable fluorescence with excitation-dependent emission behaviors. Further, the as-synthesized NN-CDs were a good fluorometric sensor for the detection of heavy metal ions in an aqueous medium. The NN-CDs showed sensitive and selective sensing platforms for Fe3+ ions; the detection limit was calculated to be 0.86 μM in the dynamic range of 5–25 μM of the ferric (Fe3+) ion concentration. Moreover, these NN-CDs could expand their application as a potential candidate for biomedical applications and offer a new method of hydrothermally carbonizing waste biomass.

Carbon Dots: Synthesis, Characterizations, and Recent Advancements in Biomedical, Optoelectronics, Sensing, and Catalysis Applications

“…The detection limit of 0.86 M in the dynamic range of 5–25 M of the ferric (Fe 3+ ) ion concentration was determined by analyzing the NN-CNDs, which demonstrated sensitive and selective sensing platforms for Fe 3+ ions (Figure A). These NN-CNDs may also find new uses as promising candidates for biological applications and provide a fresh approach to hydrothermally carbonizing waste biomass . Ilham Alkian et al created a straightforward technique based on the fluorescence quenching of CNDs for the detection of cobalt ions.…”

“…(C) The CQD solution observed fluorescence at room temperature before (left) and after (right) the addition of Cu 2+ ions. Reproduced with permission from ref . Copyright 2023 MDPI AG (Multidisciplinary Digital Publishing Institute).…”

“…These NN-CNDs may also find new uses as promising candidates for biological applications and provide a fresh approach to hydrothermally carbonizing waste biomass. 209 Overall, their results point to the effect of functional groups on CNDs' quantum yield and detection limit, which will be helpful in the continued development of CNDs for sensing applications. Figure 24B shows a synthesis schematic of CNDs and cobalt ion detection.…”

One-pot synthesis of carbon dots from neem resin and the selective detection of Fe(ii) ions and photocatalytic degradation of toxic dyes

“…17 CDs have several advantages in their optical properties, such as their broadened optical absorption, color-tunable emission, good fluorescence quantum yield, and good photobleaching resistance. 18 Owing to these remarkable features, they have garnered immense interest for their potential applications in areas such as bioimaging, 19 sensing, 20 electrochemical studies, 21 and energy storage. To maintain the excellent optical properties of CDs without reducing production costs, researchers have explored various methods for synthesizing CDs based on a variety of precursors, including organic compounds, agricultural waste, natural polymers, 22 and plant extracts.…”

Layer-by-Layer Immobilization of DNA Aptamers on Ag-Incorporated Co-Succinate Metal–Organic Framework for Hg(II) Detection

“…Heavy metal ions (HMIs) are pervasive environmental pollutants known for their detrimental health effects and ecological consequences [ 1 , 2 ]. Heavy metals can enter the environment through industrial discharges, agricultural runoff, mining, and even natural erosion, and they tend to accumulate in soils, water bodies, and the food chain [ 3 , 4 , 5 ]. This persistence can lead to the bioaccumulation of heavy metals in living organisms, posing severe health risks to humans and wildlife.…”