One-Step Facile Synthesis of Fluorescent Carbon Dots via Magnetic Hyperthermia Method

Abstract

We report here the fast fabrication of fluorescent carbon dots (CDs) within several minutes by magnetic hyperthermia. This method offers an alternative platform to prepare excitation-dependent fluorescent CDs without any surface modification from various kinds of precursors varying from polymers like poly­(vinyl alcohol) (PVA) and polyethylene glycol (PEG) to small organic molecules and salts like amino acid, glucose, EDTA, citrate acid–urea, sodium citrate, zinc stearate, and ammonium citrate. As an example, the magnetic hyperthermia synthesis, characterization, optical properties, and in vitro cytotoxicity of CDs obtained from ammonium citrate are thoroughly investigated. The excitation-dependent fluorescence mechanism is discussed based on the UV–vis absorption, excitation, and emission spectra as well as the photoluminescence (PL) response to metal ions and pH. These CDs are further used as ink for inkjet printing to produce fluorescent patterns with uniform and stable PL useful for anticounterfeit and optoelectronic applications. This magnetic hyperthermia method allows the rapid fabrication of versatile CDs from a wide range of carbon sources in a simple, low-cost, and easy-to-perform way.

Green and continuous microflow synthesis of fluorescent carbon quantum dots for bio‐imaging application

“…The N1s spectrum exhibits two peaks at 399.8 eV and 401.1 eV, representing pyrrolic N (N part of a pentagon ring connected to two C) and graphite N (N connected to three C) 26 . The O1s band can be deconvoluted into three peaks at 530.8 eV, 532.1 eV, and 532.9 eV, corresponding to the O1s states in COH/COC, CO, and bounded water (HOH), respectively 27 . These observations are in consistent with FTIR results, indicating the M‐CQDs are effectively doped by heteroatoms, and their surface are functionalized with COH, COOH, NH 2 , and CNO groups.…”

Biopolymer-Mushroom Nanofiber Composite Xerogel Film: Bio-Base-Mediated Green, Chemically Resistant, Edible, and Printable Films

“…The excitation-dependent fluorescence is the characteristic property of the CDs. 43,44 The PL decay was studied for the BCE CDs by using the time-correlated single photon counting (TCSPC) method. The experiment was carried out by using a 375 nm pulse laser as an excitation source.…”

“…49 The BCE CDs showed peaks around 1114 cm −1 corresponding to epoxy groups (C−O− C). 43 The peak near 900−667 cm −1 is due to the aromatic outof-plane C−H bending. 36 Thus, the presence of a hydrophilic group on the carbon dots facilitates the solubilization of CDs in water.…”

Novel Metal-Free Fluorescent Sensor Based on Molecularly Imprinted Polymer N-CDs@MIP for Highly Selective Detection of TNP

“… 32 , 33 CDs have received a lot of attention because of their outstanding properties, such as fluorescence, good stability, ease of synthesis, biocompatibility, low toxicity, easy surface functionalization, cost feasibility, safety, and environmentally friendly nature. 34 , 35 CDs can be made using a variety of techniques such as chemical and thermal oxidation of carbon compounds, 36 , 37 graphite laser ablation, 38 one-step microwave synthesis, 39 magnetic hyperthermia, 40 hydrothermal processes, 41 and electrochemical oxidation. 42 CDs have traditionally been used to identify various analytes like metal ions and pollutant drugs because they can act as an optical sensor or sensor material.…”

“…Semiconductor quantum dots (QDs) and their peculiar fluorometric properties have received a lot of attention in recent years. However, due to the toxic nature of the materials used in their manufacture, the applications of these types of QDs are limited. , CDs have attracted a lot of attention recently because of their superior properties to traditional semiconductor QDs. − CDs are a form of carbon nanomaterial that has been widely used as a fluorescent material for the identification of multiple analytes, such as contaminants in the environment. , CDs have received a lot of attention because of their outstanding properties, such as fluorescence, good stability, ease of synthesis, biocompatibility, low toxicity, easy surface functionalization, cost feasibility, safety, and environmentally friendly nature. , CDs can be made using a variety of techniques such as chemical and thermal oxidation of carbon compounds, , graphite laser ablation, one-step microwave synthesis, magnetic hyperthermia, hydrothermal processes, and electrochemical oxidation . CDs have traditionally been used to identify various analytes like metal ions and pollutant drugs because they can act as an optical sensor or sensor material .…”