Biogenic Synthesis of Fluorescent Carbon Dots at Ambient Temperature Using Azadirachta indica (Neem) gum (original) (raw)

Synthesis of ecofriendly fluorescent carbon dots and their biomedical and environmental applications

Materials Technology, 2018

Green Synthesis of nanoparticles is an emerging field with enormous advantages over conventional synthesis methods. Herein we have reported a green method for the preparation of water soluble polydisperse carbon dots (c-dots) from Cocos nucifera frond pinnae by a modified version of the 'single step hydrothermal carbonization'. C-dots having blue emission were obtained with this method and we further evaluated the effect of metal ions interactions on c-dots, as a sharp decrease in photoluminescence was observed. The synthesized c-dots were found bioactive against B.subtilis, M. smegmatis and S. aureus as determined by the well diffusion assay. We also explored nanotheranostic applications of c-dots as biosensor matrix in DNA hybridization sensor for pancreatic cancer and in bioimaging of cancer cells. This study demonstrated that c-dots can be explored for numerous biomedical and environmental applications in a variety of fields owing to the cost effective synthesis, biocompatibility and excellent physico-chemical properties.

Bio-Derived Fluorescent Carbon Dots: Synthesis, Properties and Applications

Molecules

The transformation of biowaste into products with added value offers a lucrative role in nation-building. The current work describes the synthesis of highly water-soluble, luminous carbon quantum dots (CQDs) in the size range of 5–10 nm from discarded rice straw. The small spherical CQDs that were formed had outstanding optical and luminescent qualities as well as good photostabilities. By performing quantitative multi-assay tests that included antioxidant activities, in vitro stability and colloidal assay investigations as a function of different CQD concentrations, the biocompatibility of CQDs was evaluated. To clearly visualize the type of surface defects and emissive states in produced CQDs, excitation-dependent fluorescence emission experiments have also been carried out. The “waste-to-wealth” strategy that has been devised is a successful step toward the quick and accurate detection of Cu2+ ion in aqueous conditions. The fluorescence-quenching behavior has specified the concen...

Green synthesis of biocompatible carbon dots using aqueous extract of

We are reporting highly economical plant based method for the production of luminescent water soluble carbon dots (C-dot) using Indian water plant Trapa bispinosa peel extract without adding any external oxidizing agent at 90°C. C-dots ranging from 5 to 10 nm were found in the solution with a prominent green fluorescence under UV-light (λ ex = 365 nm). UV-vis spectra recorded at different time intervals (30-120 min) displayed signature absorption of C-dots between 400 and 600 nm. Fluorescence spectra of the dispersion after 120 min of synthesis exhibited characteristic emission peaks of C-dots when excited at 350, 400, 450 and 500 nm. C-dots were further analyzed using X-ray diffraction (XRD), Raman Spectroscopy and Thermo-Gravimetric Analysis (TGA). Structure of the C-dots was found to be turbostratic when studied using XRD. C-dots synthesized by our method were found to be exceptionally biocompatible against MDCK cells.

Synthesis and characterization of Indian essential oil Carbon Dots for interdisciplinary applications

Applied Nanoscience, 2021

In the present study Carbon Dots (CDs) derived from Indian essential oils Clove (Eugenia caryophyllata), Basil (Ocimum basilicium), Turmeric (Curcuma longa) and Cardamom (Elettaria cardamomum) have been synthesized and characterized for their potential exquisite applications. The CD nanoscale particles were synthesized using simple green pyrolysis method without engaging external agents. The particles were well below 10 nm in size and showed activities unparallel to that of conventional CDs. Spectroscopy techniques viz. UV-Visible, Fluorescence, FT-IR, TEM were employed for the characterization of CDs while biological activity was tested on sliced bread and spinach (Spinacia oleracea). Further, human MCF-7 cell line was used to study the antiproliferative effects of the CDs in vitro. Our CDs formulation exhibit variable fungal activity and excellent growth retarding potential in addition to their antiproliferative effect. The low cost, ease of synthesis and superior properties of these CDs synthesized from Indian essential oils may represent as a viable and true contender to their traditional counterparts. On a concluding note, this work also highlights the future prospects of the potential use of CDs based nanoparticles and their unpopular characteristics.

Multifaceted applications of green carbon dots synthesized from renewable sources

Advances in Colloid and Interface Science, 2019

Fluorescent carbon dots (CDs) are an emerging class of nanomaterials in the carbon family. There are various inexpensive and renewable resources that can be used to synthesize green CDs, which have received immense attention from researchers because of their improved aqueous solubility, high biocompatibility, and eco-friendly nature compared with chemically derived CDs. Additional surface passivation is not required, as heteroatoms are present on the surface of green CDs in the form of amine, hydroxyl, carboxyl, or thiol functional groups, which can improve their physicochemical properties, quantum yield, and the probability of visible light absorption. Green CDs have potential applications in the fields of bioimaging, drug/gene delivery systems, catalysis, and sensing. Since their discovery, there have been several review articles that describe the synthesis of green CDs and some of their applications. However, there are no review articles describing the synthesis and complete applications of green CDs. Here, we provide detailed information regarding their synthesis and applications based on the available literature. In addition, we discuss some of the less explored applications of green CDs and the challenges that remain to be overcome.

Multi-functional fluorescent carbon dots with antibacterial and gene delivery properties

RSC Adv., 2015

Glucose is abundant in nature and can be found in various sources. In this study, we developed multifunctional carbon dots (CDs) with glucose and poly(ethyleneimine) (PEI), which were further quaternized using a facile approach. The CDs are designed to possess both antibacteria and gene delivery capabilities. The inherent property was characterized with TEM, NMR, FTIR and fluorescent spectroscopy.

A green and facile approach for the synthesis of water soluble fluorescent carbon dots from banana juice

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 uC 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.

Controllable Synthesis of Fluorescent Carbon Dots and Their Detection Application as Nanoprobes

Nano-Micro Letters, 2013

Carbon dots (CDs), as a new member of carbon nanomaterial family, have aroused great interest since their discovery in 2004. Because of their outstanding water solubility, high sensitivity and selectivity to target analytes, low toxicity, favorable biocompatibility, and excellent photostability, researchers from diverse disciplines have come together to further develop the fundamental properties of CDs. Many methods for the production of CDs have been reported, therein, hydrothermal and solvothermal technology needs simple equipments, and microwave synthesis needs less reaction time, hence these methods become current common synthesis methods, in which many precursors have been applied to produce CDs. Due to their excellent fluorescence, CDs have made impressive strides in sensitivity and selectivity to a diverse array of salt ions, organic/biological molecules and target gases. The development of CDs as nanoprobes is still in its infancy, but continued progress may lead to their integration into environmental and biological applications. Hydrothermal, solvothermal, and microwave synthesis of fluorescent carbon dots and their detection applications as nanoprobes in salt ions, organic/biological molecules, and target gases will be reviewed.

Recent advance of carbon dots in bio-related applications

Journal of Physics: Materials, 2020

Carbon dots (CDs) is a kind of carbon nanoparticles with a plentiful of surface functional groups and tunable emission with different excitation wavelength. Broadly speaking, CDs include carbon nanodots, carbon quantum dots, graphene quantum dots, carbonized polymer dots. Due to the unique nature, they are explored for various applications in the bio-related fields such as bioimaging, sensor for ion and (bio)molecules, catalyst, LED and other fields. They are viewed as great alternative tracers to the current fluorescent biomarkers in personalized nanomedicine and surgery operation monitoring. In this review, we summarized the recent progress in the development of CDs, including improvement in fluorescence properties, two-photon fluorescence, and integration with other modalities as theragnostic agents. Specifically, we discussed the preparation of dual-modal imaging agents to improve the accuracy of diagnosis, the combination of imaging and targeting functionality for the effective...