Synthesis of fluorescent carbon dots via microwave carbonization of citric acid in presence of tetraoctylammonium ion, and their application to cellular bioimaging

Bhaisare, Mukesh Lavkush; Talib, Abou; Khan, M. Shahnawaz; Pandey, Sunil; Wu, Hui‐Fen

doi:10.1007/s00604-015-1541-5

Cited by 107 publications

(55 citation statements)

References 36 publications

(35 reference statements)

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“…This is consistent with the FTIR and XPS data shown in Section . These surface‐functionalized SF‐CQDs also exhibit good colloidal stability in water and this good hydrophilicity is a favorable property to allow for further modification and applications in the biomedical field including drug delivery and diagnostics …”

Section: Resultsmentioning

confidence: 99%

Microwave‐Assisted Synthesis of Biocompatible Silk Fibroin‐Based Carbon Quantum Dots

Nafiujjaman

Cherukula

et al. 2017

Part & Part Syst Charact

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A biocompatible silk fibroin‐based carbon quantum dot (SF‐CQD) is first synthesized under microwave irradiation for a short time. This fast and environmentally safe technique produce well‐defined nanosized SF‐CQDs. The SF‐CQDs have good crystallinity, a strong emission peak in the blue‐color region, high quantum yield, and the potential for modification with various functional groups on the surface. These SF‐CQDs demonstrate stable emission, good water dispersity, low toxicity, and good biocompatibility. These properties show the great potential of these SF‐CQDs for use in biomedical applications including bioimaging, biosensing, and drug delivery systems.

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Section: Resultsmentioning

confidence: 99%

Microwave‐Assisted Synthesis of Biocompatible Silk Fibroin‐Based Carbon Quantum Dots

Nafiujjaman

Cherukula

et al. 2017

Part & Part Syst Charact

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“…Later, Bhaisare et al synthesized jellylike CDs with CA and tetraoctylammonium bromide (TOAB) using microwave assisted heating (at maximum 500 watt). [56] Four unique CA to TOAB ratios (5g CA: 2/4/6/8 mL of 0.1 M TOAB) were applied in the synthesis, with the obtained CDs named as C-dots I, II, III, and IV, respectively. The authors also reported that an optimum reaction time of 2–3 min produced the desired yellowish CDs.…”

Section: Citrate-based Carbon Dots (Cds)mentioning

confidence: 99%

“…To demonstrate the in vitro cell labeling capability of CDs, Bhaisare et al developed a type of biocompatible CDs with excitation-dependent fluorescence from CA and tetraoctylammonium bromide, and applied these CDs to label HeLa cells under blue fluorescence. [56] Zholobak also applied CDs synthesized from CA and urea for live/fixed diploid epithelial swine testicular cell line (ST-cells) staining. [74] Furthermore, in vivo bioimaging was also conducted with citrate-based CDs.…”

Section: Citrate-based Carbon Dots (Cds)mentioning

confidence: 99%

Citrate‐Based Fluorescent Biomaterials

Shan

Hsieh

Bai

et al. 2018

Adv Healthcare Materials

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Fluorescence imaging has emerged as a promising technique for monitoring and assessing various biologically relevant species in cells and organisms, driving the demand for effective fluorescent agents with good biocompatibility and high fluorescence performance. However, traditional fluorescent agents, such as quantum dots (QDs) and organic dyes, either suffer from toxicity concerns or poor fluorescence performance (e.g., low photobleaching-resistance). In this regard, citrate-based fluorescent biomaterials, which are synthesized from the natural and biocompatible precursor of citric acid (CA), have become competitive alternatives for fluorescence imaging owing to their biocompatibility, cost effectiveness, straightforward synthetic routes, flexible designability, as well as strong fluorescence with adjustable excitation/emission wavelengths. Accordingly, numerous citrate-based biomaterials, including carbon dots (CDs), biodegradable photoluminescent polymers (BPLPs), and small molecular fluorophores, have been developed and researched in the past few decades. This review discusses recent progress in the research and development of citrate-based fluorescent materials with emphasis on their design and synthesis considerations, material properties, fluorescence properties and mechanisms, as well as biomedical applications. It is expected that this review will provide an insightful discussion on the citrate-based fluorescent biomaterials, and lead to innovations for the next generation of fluorescent biomaterials and fluorescence-based biomedical technology.

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“…The XRD spectrum of RCD is narrower than that of PCD, implying less amorphous structural feature of RCD compared to PCD. The broad peak is due to the various functional groups existing in CD structure and its small size . FTIR spectrum exhibited sharp and intense peaks such as CH stretching (2976 cm −1 ), CO stretching (1045 cm −1 ), and CH out‐of‐plane bending (879 cm −1 ) in FTIR spectrum.…”

Section: Resultsmentioning

confidence: 99%

Quenching‐Resistant Polymer Carbon Dot Preserving Emission Color Consistency in Solid‐State

Kwak

Yoo

Kim

2019

Advanced Optical Materials

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Recently, Rogach's group realized solidstate-luminescent CD/silica composite, which possessed high quantum yield (QY) and PL output with relatively high CD loading (19.2 wt%) by gelation. [18] However, this process was limited to hydroxyl-rich CD only and still suffered from aggregation in extremely high concentration.Fundamental solution is to develop a selfquenching-resistant CD even without dispersion matrices. Polymer CD (PCD), a polymer-like CD consisting of crosslinked matrix and sub-fluorophores, has been studied for solid-state luminescence because crosslinking may prevent π-π interaction. [20][21][22][23] Several groups synthesized quenching-resistant PCD, but those showed red-shifted emission with noticeable color change compared to solutionstate fluorescence. [24][25][26][27] Such spectral shift in solid-state usually occurs with nonradiative decay competitively, which leads to a decrease of QY. In addition, the emission color change in solidstate needs additional optimization process for the fabrication of optoelectronics, so that the energy transfer as an origin for ACQ and red-shift should be strictly avoided.Herein, we synthesized a blue-emitting PCD with the same emission center at 434 nm in both solution-and solid-state through a hydrothermal reaction. By structural and spectroscopic analysis, the origin of solid-state luminescence was investigated. We further identified a reason for the emission color consistency of PCD from dilute solution to powder form by comparing with CD that showed red-shifted emission in solid-state. We also fabricated LED using PCD as a color-converting layer, and it had a luminous efficacy of 12.03 lm W −1 without significant color change even with extremely high loading fraction of 50 wt%. With the increased loading fraction (20 wt%), we enhanced brightness of our LED up to four times compared to the LED fabricated with conventional low loading fraction (0.1-5 wt%) using PCD. Compared to red-shifted CD (RCD)-based LED with the conventional loading fraction, the luminous flux of PCD-based LED with 20 wt% increased by 3 to 15 times. This result would be a great interest to those who study CD-based LED. Results and DiscussionSolid-state luminescent polymer carbon dot (PCD) was synthesized using citric acid (CA) and diethylenetriamine (DETA) through a hydrothermal reaction at 70 °C (Figure 1a). Product Solid-state luminescent carbon dot without dispersion matrices is studied to overcome aggregation-caused quenching, but it usually shows spectral shift between solution-and solid-state accompanying a dramatic decrease of fluorescence intensity, which hinders a real application. Herein, polymer carbon dot (PCD) showing solid-state luminescence without red-shift is synthesized by low-temperature reaction. The PCD solution and solid have the same emission peaks at 434 nm and similar absolute quantum yields of 68.2% and 62.7%, respectively, which is uncommon feature compared to other carbon dots. The mechanism for solid-state luminescence and emission color consistency is invest...

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Synthesis of fluorescent carbon dots via microwave carbonization of citric acid in presence of tetraoctylammonium ion, and their application to cellular bioimaging

Cited by 107 publications

References 36 publications

Microwave‐Assisted Synthesis of Biocompatible Silk Fibroin‐Based Carbon Quantum Dots

Microwave‐Assisted Synthesis of Biocompatible Silk Fibroin‐Based Carbon Quantum Dots

Citrate‐Based Fluorescent Biomaterials

Quenching‐Resistant Polymer Carbon Dot Preserving Emission Color Consistency in Solid‐State

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