Green synthesis of carbon dots from Ocimum sanctum for effective fluorescent sensing of Pb2+ ions and live cell imaging
TL;DR: In this article, a simple, rapid and cost-effective approach is developed to synthesize fluorescent carbon dots (CDs) using the leaves of Ocimum sanctum as a carbon source for the first time.
Abstract: A simple, rapid and cost-effective approach is developed to synthesize fluorescent carbon dots (CDs) using the leaves of Ocimum sanctum as a carbon source for the first time. The as-synthesized CDs possess high stability in aqueous solution and exhibit strong fluorescence with quantum yield of 9.3%. We have explored the use of such CDs as a fluorescent sensor for Pb2+ ions detection, which is based on Pb2+ ions induced fluorescence quenching of CDs. More significantly the resultant CDs has excellent selectivity and sensitivity towards Pb2+ ions with a limit of detection (LOD) 0.59 nM and linear detection range of 0.01–1.0 μM. The practical use of synthesized CDs for detection of Pb2+ ions is demonstrated in triple negative breast cancer cells (MDA-MB 468 cells) and real water samples successfully. Moreover, the CDs are also possessing low cytotoxicity to exhibit excellent fluorescent probe for multicolour cellular imaging.
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TL;DR: It is proved that synthesized FNCDs has durable fluorescence, soluble in water very well and thus act as a promising candidate for the diverse applications such as label-free sensitive and selective detection of Fe3+, fluorescent ink and cellular imaging with good biocompatibility and low cytotoxicity.
498 citations
TL;DR: Carbon quantum dots (CQDs) as discussed by the authors are a new class of fluorescence small carbon nanoparticles with a particle size of less than 10nm and have vast applications in the field of bioimaging, biosensing and disease-detection.
431 citations
TL;DR: This review summarizes the latest developments available in literature regarding the use of QDs for medical applications and indicates an increasing interest in the development of nano-theranostics platforms for simultaneous sensing, imaging and therapy.
Abstract: Quantum dots (QDs), also known as nanoscale semiconductor crystals, are nanoparticles with unique optical and electronic properties such as bright and intensive fluorescence. Since most conventional organic label dyes do not offer the near-infrared (>650 nm) emission possibility, QDs, with their tunable optical properties, have gained a lot of interest. They possess characteristics such as good chemical and photo-stability, high quantum yield and size-tunable light emission. Different types of QDs can be excited with the same light wavelength, and their narrow emission bands can be detected simultaneously for multiple assays. There is an increasing interest in the development of nano-theranostics platforms for simultaneous sensing, imaging and therapy. QDs have great potential for such applications, with notable results already published in the fields of sensors, drug delivery and biomedical imaging. This review summarizes the latest developments available in literature regarding the use of QDs for medical applications.
419 citations
TL;DR: This study reviews the journey of green c-dots by means of green sources of synthesis and their applications, with the major focus on various sensors and bioimaging probes.
Abstract: The past decade has witnessed the emergence of carbon dots (c-dots), outshining other members of the carbon family because of their outstanding properties in fluorescence, cytocompatibility, photostability, electronic, mechanical and other chemical properties. This has resulted in an increasing number of applications in bioimaging, sensing, photovoltaic and medicine. Nature offers a wealth of exciting precursors that motivate constant persuasion of benign synthetic routes. Consequently, the past 5 years has seen a tremendous rise in green synthetic approaches of c-dots. This study reviews the journey of green c-dots by means of green sources of synthesis and their applications, with the major focus on various sensors and bioimaging probes.
330 citations
TL;DR: CQDs, their structure, and PL characteristics are introduced and recent advances of the application of CQDs in biotechnology, sensors, and CL is comprehensively discussed.
286 citations
References
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TL;DR: In this article, the results of the elemental analysis with that obtained by different spectroscopic techniques (infrared and Raman spectroscopy, and XPS) have been inferred that, from a chemical point of view, the solid product consists of small clusters of condensed benzene rings that form stable groups with oxygen in the core.
1,526 citations
TL;DR: Highly photoluminescent carbon dots with a PL quantum yield of 26% have been prepared in one step by hydrothermal treatment of orange juice and demonstrated as excellent probes in cellular imaging.
1,314 citations
TL;DR: In this article, green luminescent water soluble oxygenous carbon dots with an average size of 3 nm were synthesized by simply heating banana (Musa acuminata) juice at 150 °C for 4 h without using any surface passivating and oxidizing agent or inorganic salt.
Abstract: Green luminescent water soluble oxygenous carbon dots with an average size of 3 nm were synthesized by simply heating banana (Musa acuminata) juice at 150 °C for 4 h without using any surface passivating and oxidizing agent or inorganic salt. The literature was used to propose a possible mechanism for the formation of carbon dots by this approach. The resulting carbon dots exhibited concentration, excitation wavelength and pH dependent luminescent behavior in the visible range. The quantum yield was 8.95 on excitation at a wavelength of 360 nm, using quinine sulfate as the reference. The presence of large amounts of oxygenous functionality was confirmed by FTIR and EDX studies. XRD and TEM illustrated the poor crystalline nature and narrow distribution of these spherical carbon dots. Thus bio-based fluorescent carbon dots with a high yield were reported for the first time through a simple and effective route without using any special apparatus or reagents.
658 citations
TL;DR: Nitrogen and sulfur codoped carbon dots prepared from garlic by a hydrothermal method demonstrated to possess good water dispersibility, strong blue fluorescence emission, and excellent photo and pH stabilities, and could be used as an excellent fluorescent probe for cellular multicolor imaging.
Abstract: Nitrogen and sulfur codoped carbon dots (CDs) were prepared from garlic by a hydrothermal method. The as-prepared CDs possess good water dispersibility, strong blue fluorescence emission with a fluorescent quantum yield of 17.5%, and excellent photo and pH stabilities. It is also demonstrated that the fluorescence of CDs are resistant to the interference of metal ions, biomolecules, and high ionic strength environments. Combining with low cytotoxicity properties, CDs could be used as an excellent fluorescent probe for cellular multicolor imaging. Moreover, the CDs were also demonstrated to exhibit favorable radical scavenging activity.
427 citations
TL;DR: It was shown that the prepared CDs had no toxic effect on the both cells lines (bacteria and fungal), indicating that the CDs did not inhibit growth of bacterial andFungal cells, which confirms that the CD exhibit good biocompatibility.
Abstract: A facile green hydrothermal method was developed for the preparation of fluorescent carbon dots (CDs) using apple juice as a raw material. The synthesized fluorescent CDs were characterized by UV–vis, fluorescence, Fourier transform infrared (FT-IR), dynamic light scattering (DLS), high resolution transmission electron microscopic (HR-TEM), life-time measurement and laser scanning confocal microscopic techniques. The CDs showed bright blue emission under UV-light ( λ ex = 365 nm). The CDs were used as alternative biocompatible fluorescent probes for imaging of bacteria ( Mycobacterium tuberculosis and Pseudomonas aeruginosa ) and fungal ( Magnaporthe oryzae ). It was shown that the prepared CDs had no toxic effect on the both cells lines (bacteria and fungal), indicating that the CDs did not inhibit growth of bacterial and fungal cells, which confirms that the CDs exhibit good biocompatibility.
373 citations