scholarly journals Preparation and Characterization of Bacterial Cellulose-Carbon Dot Hybrid Nanopaper for Potential Sensing Applications

2018 ◽  
Vol 9 (1) ◽  
pp. 107 ◽  
Author(s):  
Sakeena Quraishi ◽  
Sven Plappert ◽  
Bernhard Ungerer ◽  
Philip Taupe ◽  
Wolfgang Gindl-Altmutter ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Bacterial Cellulose ◽  
Optical Sensors ◽  
Carbon Dots ◽  
Carbon Nanodots ◽  
Excitation Wavelength ◽  
Single Digit ◽  
Water Contact ◽  
Isolation And Purification ◽  
Sensing Applications

Green and facile approaches aiming at the manufacture of biocompatible paper-based optical sensors reporting the presence of photoluminescence (PL) modulating compounds is an emerging field of research. This study investigates the preparation of bacterial cellulose nanopaper containing covalently immobilized carbon dots for potential biosensing applications. Preliminary work of this feasibility study included TEMPO-mediated ((2,2,6,6-tetramethylpiperidin-1-yl)oxyl-mediated) oxidation and nanofibrillation of bacterial cellulose (TOBC) on the one hand as well as synthesis and comparative analysis of different types of carbon dots (CDs) on the other hand. The two source materials of the targeted functional nanopaper were finally linked to each other by two different N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride/ N-hydroxysuccinimide (EDC/NHS) coupling approaches to clarify whether grafting of CDs prior to or after TOBC paper formation would be the method of choice. Synthesis of the carbon nanodots was accomplished by microwave-assisted co-hydrothermolysis of appropriate precursor compounds. After isolation and purification by dialysis particles in the single-digit nanometer-range were obtained and characterized with regard to their photoluminescence properties in terms of emission wavelength, pH stability, and quantum yield. All types of synthesized CDs reached their PL maxima (450–480 nm; light blue) in a narrow excitation wavelength range of 340–360 nm. Variation of molar (C/N) ratio of the CD precursors and substitution of the nitrogen donor EDEA by urea increased PL and quantum yield (QY), respectively. The highest relative QY of nearly 32% was obtained for CDs synthesized from citric acid and urea. PL of all CDs was virtually insensitive to pH changes in the range of 4–10. Tensile testing of hybrid nanopaper prepared after EDC/NHS-mediated grafting of GEA-type CDs onto TOBC (0.52 mmol·g−1 COOH) in dispersion state revealed that both stiffness and strength are not compromised by incorporation of carbon dots, while plastic deformation and elongation at break increased slightly compared to nanopaper formed prior to decoration with CDs. Water contact angle of the nanopaper is unaffected by introduction of carbon dots which is supposedly due to the presence of surface amino- and amide groups compensating for the loss of carboxyl groups by grafting.

scholarly journals Recent Advancements in Doped/Co-Doped Carbon Quantum Dots for Multi-Potential Applications

2019 ◽  
Vol 5 (2) ◽  
pp. 24 ◽  
Author(s):  
Ganeshlenin Kandasamy
Keyword(s):  
Quantum Dots ◽  
Optical Sensors ◽  
Carbon Nanomaterials ◽  
Synthesis Method ◽  
Carbon Quantum Dots ◽  
Carbon Nanodots ◽  
Synthesis Methods ◽  
Sensing Applications ◽  
Potential Applications ◽  
Co Doped

Carbon quantum dots (CQDs)/carbon nanodots are a new class of fluorescent carbon nanomaterials having an approximate size in the range of 2–10 nm. The majority of the reported review articles have discussed about the development of the CQDs (via simple and cost-effective synthesis methods) for use in bio-imaging and chemical-/biological-sensing applications. However, there is a severe lack of consolidated studies on the recently developed CQDs (especially doped/co-doped) that are utilized in different areas of application. Hence, in this review, we have extensively discussed about the recent development in doped and co-doped CQDs (using elements/heteroatoms—e.g., boron (B), fluorine (F), nitrogen (N), sulphur (S), and phosphorous (P)), along with their synthesis method, reaction conditions, and/or quantum yield (QY), and their emerging multi-potential applications including electrical/electronics (such as light emitting diode (LED) and solar cells), fluorescent ink for anti-counterfeiting, optical sensors (for detection of metal ions, drugs, and pesticides/fungicides), gene delivery, and temperature probing.

scholarly journals Polyol-Mediated Synthesis of Nitrogen-Containing Carbon-Dots from Tetracyanobenzene with Intense Red Fluorescence

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1470 ◽  
Author(s):  
Roman Lehmacher ◽  
Claus Feldmann
Keyword(s):  
Polyethylene Glycol ◽  
Liquid Phase ◽  
Quantum Yield ◽  
Carbon Dots ◽  
Emission Spectra ◽  
Excitation Wavelength ◽  
Polyethylene Glycol 400 ◽  
Strong Emission ◽  
Red Emission ◽  
Naked Eye

Nitrogen-containing C-dots were prepared by heating (160 °C, 1 h) 1,2,4,5-tetracyanobenzene (TCB) in polyethylene glycol 400 (PEG400). The as-prepared monocrystalline C-dots were 2–4 nm in diameter and contained 24.4 wt. % of nitrogen. They showed intense fluorescence under excitation at 400–500 nm as well as under excitation at 600–700 nm. In addition to an excitation-wavelength-depending emission at 400 to 650 nm, the emission spectra exhibited a strong emission peaking at 715 nm, whose position was independent from the wavelength of excitation. For this deep-red emission a remarkable quantum yield of 69% was detected. The synthesis of nitrogen-containing C-dotswas completely performed in the liquid phase. Moreover, the C-dots could be directly dispersed in water. The resulting aqueous suspensions of PEG400-stabilized nitrogen-containing C-dots also showed intense red emission that was visible to the naked eye.

scholarly journals A Comparative Study of Top-Down and Bottom-Up Carbon Nanodots and Their Interaction with Mercury Ions

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1265
Author(s):  
Federico Bruno ◽  
Alice Sciortino ◽  
Gianpiero Buscarino ◽  
Maria Laura Soriano ◽  
Ángel Ríos ◽  
...  
Keyword(s):  
Optical Properties ◽  
Carbon Dots ◽  
Carbon Nanodots ◽  
Fluorescent Nanoparticles ◽  
Mercury Ions ◽  
Top Down ◽  
Structural And Optical Properties ◽  
Bottom Up ◽  
Interaction Sites ◽  
Sensing Applications

We report a study of carbon dots produced via bottom-up and top-down routes, carried out through a multi-technique approach based on steady-state fluorescence and absorption, time-resolved fluorescence spectroscopy, Raman spectroscopy, infrared spectroscopy, and atomic force microscopy. Our study focuses on a side-to-side comparison of the fundamental structural and optical properties of the two families of fluorescent nanoparticles, and on their interaction pathways with mercury ions, which we use as a probe of surface emissive chromophores. Comparison between the two families of carbon dots, and between carbon dots subjected to different functionalization procedures, readily identifies a few key structural and optical properties apparently common to all types of carbon dots, but also highlights some critical differences in the optical response and in the microscopic mechanism responsible of the fluorescence. The results also provide suggestions on the most likely interaction sites of mercury ions at the surface of carbon dots and reveal details on mercury-induced fluorescence quenching that can be practically exploited to optimize sensing applications of carbon dots.

scholarly journals Fluorescent N-doped carbon dots from bacterial cellulose for highly sensitive bacterial detection

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 78-88
Author(s):  
Shunli Li ◽  
Xin Zhao ◽  
Yujie Zhang ◽  
Honglei Chen ◽  
Yu Liu
Keyword(s):  
Bacterial Cellulose ◽  
Carbon Dots ◽  
High Performance ◽  
Hydrothermal Carbonization ◽  
Excitation Wavelength ◽  
Particle Sizes ◽  
Bacterial Detection ◽  
Highly Sensitive ◽  
Wide Range ◽  
Doped Carbon Dots

Carbon dots have good dispersion capability, strong visible fluorescence, low toxicity, and photo-induced accepting and donating abilities. Carbon dots were obtained from biomass bacterial cellulose (BC) via one-step hydrothermal carbonization. Effects of hydrothermal time and temperature on the microstructure, fluorescence, and excitation wavelength dependent photoluminescence (PL) behavior were explored for the prepared carbon dots. The results showed that the carbon dots obtained directly from the BC (C dots) had small particle sizes (2.0 to 3.0 nm) and green luminescence behavior. Conversely, the N-doped carbon dots (N-C dots) exhibited more uniform and smaller particle sizes (approximately 1.0 nm), strong blue luminescence, acceptable fluorescence lifetime, and good stability in a wide range of pH values (2.0 to 10.0). Thus, carbon dots could serve as a fluorescent material used in high performance optical cellular imaging and highly sensitive bacterial detection.

Novel fluorescence resonance energy transfer optical sensors for vitamin B12 detection using thermally reduced carbon dots

2015 ◽  
Vol 39 (1) ◽  
pp. 501-507 ◽  
Author(s):  
Jilong Wang ◽  
Junhua Wei ◽  
Siheng Su ◽  
Jingjing Qiu
Keyword(s):  
Energy Transfer ◽  
Quantum Yield ◽  
Vitamin B12 ◽  
Fluorescence Resonance Energy Transfer ◽  
Optical Sensors ◽  
Carbon Dots ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Fold Increase ◽  
Thermal Reduction

After thermal reduction, the quantum yield of thermally reduced carbon dots demonstrated a 5-fold increase over that of the original carbon dots.

scholarly journals Efficient removal of Cu(ii) from aqueous systems using enhanced quantum yield nitrogen-doped carbon nanodots

RSC Advances ◽  
2020 ◽  
Vol 10 (25) ◽  
pp. 14979-14990 ◽  
Author(s):  
Mohammed Abdullah Issa ◽  
Zurina Z. Abidin ◽  
Musa Y. Pudza ◽  
Hamid Zentou
Keyword(s):  
Quantum Yield ◽  
Carbon Dots ◽  
Value Added ◽  
Carbon Nanodots ◽  
Contaminated Water ◽  
Aqueous Systems ◽  
Efficient Removal ◽  
Copper Adsorption ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

Low value waste resources have been converted into value-added luminescence carbon dots for copper adsorption from contaminated water.

On the Nature of Solvothermally Synthesized Carbon Dots

2021 ◽  
Author(s):  
Sergio Ramírez-Barroso ◽  
Alejandra Jacobo-Martín ◽  
Iván Navarro-Baena ◽  
Jaime J. Hernandez ◽  
Cristina Navio ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Carbon Dots ◽  
Carbon Nanodots ◽  
Facile Synthesis

Due to their facile synthesis, biocompatibility, high apparent photoluminescence (PL) quantum yield and applications in photocatalysis, sensing and biomarkers carbon nanodots (CNDs) have been investigated intensively in recent years. Solvothermal...

Fluorescent Nanotechnology: An Evolution in Optical Sensors

2020 ◽  
Vol 17 ◽  
Author(s):  
Dilawar Hassan ◽  
Hadi Bakhsh ◽  
Asif M. Khurram ◽  
Shakeel A. Bhutto ◽  
Nida S. Jalbani ◽  
...  
Keyword(s):  
Optical Properties ◽  
Optical Sensors ◽  
Light Emission ◽  
Environmental Contaminants ◽  
Fluorescent Nanoparticles ◽  
Sensing Applications ◽  
Properties Of Materials ◽  
Optical Properties Of Materials ◽  
Fluorescent Nanomaterials

Background: The optical properties of nanomaterials have evolved enormously with the introduction of nanotechnology. The property of materials to absorb and/or emit specific wavelength has turned them into one of the most favourite candidates to be effectively utilized in different sensing applications e.g organic light emission diodes (OLEDs) sensors, gas sensors, biosensors and fluorescent sensors. These materials have been reported as a sensor in the field of tissue and cell imaging, cancer detection and detection of environmental contaminants etc. Fluorescent nanomaterials are heling in rapid and timely detection of various contaminants that greatly impact the quality of life and food, that is exposed to these contaminants. Later, all the contaminants have been investigated to be most perilous entities that momentously affect the life span of the animals and humans who use those foods which have been contaminated. Objective: In this review, we will discuss about various methods and approaches to synthesize the fluorescent nanoparticles and quantum dots (QDs) and their applications in various fields. The application will include the detection of various environmental contaminants and bio-medical applications. We will discuss the possible mode of action of the nanoparticles when used as sensor for the environmental contaminants as well as the surface modification of some fluorescent nanomaterials with anti-body and enzyme for specific detection in animal kingdom. We will also describe some RAMAN based sensors as well as some optical sensing-based nanosensors. Conclusion: Nanotechnology has enabled to play with the size, shape and morphology of materials in the nanoscale. The physical, chemical and optical properties of materials change dramatically when they are reduced to nanoscale. The optical properties can become choosy in terms of emission or absorption of wavelength in the size range and can result in production of very sensitive optical sensor. The results show that the use of fluorescent nanomaterials for the sensing purposes are helping a great deal in the sensing field.

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