Author
Geli Li
Bio: Geli Li is an academic researcher from Fuzhou University. The author has contributed to research in topics: Detection limit & Quantum dot. The author has an hindex of 3, co-authored 3 publications receiving 1199 citations.
Papers
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TL;DR: It is demonstrated that this facile methodology can offer a rapid, reliable, and selective detection of Cu(2+) with a detection limit as low as 6 nM and a dynamic range from 10 to 1100 nM.
Abstract: A novel sensing system has been designed for Cu2+ ion detection based on the quenched fluorescence (FL) signal of branched poly(ethylenimine) (BPEI)-functionalized carbon quantum dots (CQDs) Cu2+ ions can be captured by the amino groups of the BPEI-CQDs to form an absorbent complex at the surface of CQDs, resulting in a strong quenching of the CQDs’ FL via an inner filter effect Herein, we have demonstrated that this facile methodology can offer a rapid, reliable, and selective detection of Cu2+ with a detection limit as low as 6 nM and a dynamic range from 10 to 1100 nM Furthermore, the detection results for Cu2+ ions in a river water sample obtained by this sensing system agreed well with that by inductively couple plasma mass spectrometry, suggesting the potential application of this sensing system
872 citations
TL;DR: The result agreed well with that by the DPD colorimetric method, suggesting the potential application of this new, green, sensitive, and facile sensing system in drinking water quality monitoring.
Abstract: Free chlorine was found to be able to destroy the passivated surface of the graphene quantum dots (GQDs) obtained by pyrolyzing citric acid, resulting in significant quenching of their fluorescence (FL) signal. After optimizing some experimental conditions (including response time, concentration of GQDs, and pH value of solution), a green and facile sensing system has been developed for the detection of free residual chlorine in water based on FL quenching of GQDs. The sensing system exhibits many advantages, such as short response time, excellent selectivity, wide linear response range, and high sensitivity. The linear response range of free chlorine (R2 = 0.992) was from 0.05 to 10 μM. The detection limit (S/N = 3) was as low as 0.05 μM, which is much lower than that of the most widely used N-N-diethyl-p-phenylenediamine (DPD) colorimetric method. This sensing system was finally used to detect free residual chlorine in local tap water samples. The result agreed well with that by the DPD colorimetric met...
366 citations
TL;DR: The FL of CQD-aerogel hybrid material could be selectively and sensitively quenched by NO2 gas, suggesting a promising application of the new FL-functionalized aerogels in gas sensing.
Abstract: Silica aerogels functionalized with strongly fluorescent carbon quantum dots were first prepared and used for simple, sensitive, and selective sensing of NO2 gas. In the presence of ethanol, homemade silica aerogels with a large specific surface area of 801.17 m2/g were functionalized with branched polyethylenimine-capped quantum dots (BPEI-CQDs) with fluorescence quantum yield higher than 40%. The prepared porous CQD-aerogel hybrid material could maintain its excellent fluorescence (FL) activity in its solid state. The FL of CQD-aerogel hybrid material could be selectively and sensitively quenched by NO2 gas, suggesting a promising application of the new FL-functionalized aerogels in gas sensing.
119 citations
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TL;DR: The progress in the research and development of CQDs is reviewed with an emphasis on their synthesis, functionalization and technical applications along with some discussion on challenges and perspectives in this exciting and promising field.
Abstract: Fluorescent carbon nanoparticles or carbon quantum dots (CQDs) are a new class of carbon nanomaterials that have emerged recently and have garnered much interest as potential competitors to conventional semiconductor quantum dots. In addition to their comparable optical properties, CQDs have the desired advantages of low toxicity, environmental friendliness low cost and simple synthetic routes. Moreover, surface passivation and functionalization of CQDs allow for the control of their physicochemical properties. Since their discovery, CQDs have found many applications in the fields of chemical sensing, biosensing, bioimaging, nanomedicine, photocatalysis and electrocatalysis. This article reviews the progress in the research and development of CQDs with an emphasis on their synthesis, functionalization and technical applications along with some discussion on challenges and perspectives in this exciting and promising field.
3,514 citations
TL;DR: Carbon quantum dots (CQDs, C-dots or CDs) have found wide use in more and more fields during the last few years as discussed by the authors, focusing on their synthetic methods, size control, modification strategies, photoelectric properties, luminescent mechanism, and applications in biomedicine, optronics, catalysis and sensor issues.
Abstract: Carbon quantum dots (CQDs, C-dots or CDs), which are generally small carbon nanoparticles (less than 10 nm in size) with various unique properties, have found wide use in more and more fields during the last few years. In this feature article, we describe the recent progress in the field of CQDs, focusing on their synthetic methods, size control, modification strategies, photoelectric properties, luminescent mechanism, and applications in biomedicine, optronics, catalysis and sensor issues.
1,733 citations
TL;DR: The properties and synthesis methods of these carbon nanodots are reviewed and emphasis is placed on their biological (both fundamental and theranostic) applications.
Abstract: The emerging graphene quantum dots (GQDs) and carbon dots (C-dots) have gained tremendous attention for their enormous potentials for biomedical applications, owing to their unique and tunable photoluminescence properties, exceptional physicochemical properties, high photostability, biocompatibility, and small size. This article aims to update the latest results in this rapidly evolving field and to provide critical insights to inspire more exciting developments. We comparatively review the properties and synthesis methods of these carbon nanodots and place emphasis on their biological (both fundamental and theranostic) applications.
1,665 citations
TL;DR: The major design principles and criteria for engineering the surface functionality of C-dots for biological applications include brightness, long-term stability, and good biocompatibility are discussed.
Abstract: Nanoparticles are promising scaffolds for applications such as imaging, chemical sensors and biosensors, diagnostics, drug delivery, catalysis, energy, photonics, medicine, and more. Surface functionalization of nanoparticles introduces an additional dimension in controlling nanoparticle interfacial properties and provides an effective bridge to connect nanoparticles to biological systems. With fascinating photoluminescence properties, carbon dots (C-dots), carbon-containing nanoparticles that are attracting considerable attention as a new type of quantum dot, are becoming both an important class of imaging probes and a versatile platform for engineering multifunctional nanosensors. In order to transfer C-dots from proof-of-concept studies toward real world applications such as in vivo bioimaging and biosensing, careful design and engineering of C-dot probes is becoming increasingly important.A comprehensive knowledge of how C-dot surfaces with various properties behave is essential for engineering C-dots...
800 citations
TL;DR: Graphene quantum dots (GQDs) are nanometer-sized fragments of graphene that show unique properties, which makes them interesting candidates for a whole range of new applications as discussed by the authors.
Abstract: Graphene quantum dots (GQDs) are nanometer-sized fragments of graphene that show unique properties, which makes them interesting candidates for a whole range of new applications. This review article gives an overview of the synthesis, properties and applications of GQDs. Synthesis methods discussed include top-down and bottom-up approaches. Properties such as luminescence up- and down-conversion have been used in applications ranging from energy conversion to bio-analytics. This article provides an overview of the state-of-the-art and highlights promising findings as well as potential future directions of the research field.
758 citations