One-step synthesis of biofunctional carbon quantum dots for bacterial labeling.

In this study, we used a simple one-step dry heating method to synthesize mannose-modified fluorescent carbon quantum dots (Man-CQDs) from solid ammonium citrate and mannose, and successfully applied for labeling Escherichia coli. The highly soluble Man-CQDs had an average particle diameter of 3.1±1.2 nm and exhibited a quantum yield of 9.8% at excitation and emission wavelengths of 365 and 450 nm, respectively. The fluorescent Man-CQDs could selectively bind to the FimH lectin unit in the flagella of the wild-type 1 E. coli K12 strain. We optimized the labeling efficiency of the Man-CQDs by controlling the ratio of ammonium citrate to mannose during their synthesis. The specific binding of the mannose units to E. coli allowed quantitative detection of the bacteria at levels down to 450 colony forming units mL(-1) in lab samples, and facilitate the application of the Man-CQDs for bacterial analyses of real samples (tap water, apple juice, human urine). The synthesis of our Man-CQDs, their labeling, and their use in the detection of bacteria were all simple, inexpensive and efficient processes.

[1]  Alexander P Demchenko,et al.  Novel fluorescent carbonic nanomaterials for sensing and imaging , 2013, Methods and applications in fluorescence.

[2]  Tierui Zhang,et al.  Carbon quantum dots/TiO2 composites for efficient photocatalytic hydrogen evolution , 2014 .

[3]  X. Qu,et al.  Microwave assisted one-step green synthesis of cell-permeable multicolor photoluminescent carbon dots without surface passivation reagents , 2011 .

[4]  Moon J. Kim,et al.  Photoluminescent carbon nanoparticles produced by confined combustion of aromatic compounds , 2012 .

[5]  Abdullah M. Asiri,et al.  Green, low-cost synthesis of photoluminescent carbon dots by hydrothermal treatment of willow bark and their application as an effective photocatalyst for fabricating Au nanoparticles–reduced graphene oxide nanocomposites for glucose detection , 2013 .

[6]  Y. Hsiao,et al.  Facile synthesis of highly emissive carbon dots from pyrolysis of glycerol; gram scale production of carbon dots/mSiO2 for cell imaging and drug release , 2012 .

[7]  Ya‐Ping Sun,et al.  Crosslinked carbon dots as ultra-bright fluorescence probes. , 2013, Small.

[8]  C. Huang,et al.  A general quantitative pH sensor developed with dicyandiamide N-doped high quantum yield graphene quantum dots. , 2014, Nanoscale.

[9]  Q. Huo,et al.  Commercially activated carbon as the source for producing multicolor photoluminescent carbon dots by chemical oxidation. , 2010, Chemical communications.

[10]  Minghong Wu,et al.  Hydrothermal Route for Cutting Graphene Sheets into Blue‐Luminescent Graphene Quantum Dots , 2010, Advanced materials.

[11]  Angel Orte,et al.  Fluorescent nanoparticles for intracellular sensing: a review. , 2012, Analytica chimica acta.

[12]  Ahjeong Son,et al.  Development and characterization of a magnetic bead-quantum dot nanoparticles based assay capable of Escherichia coli O157:H7 quantification. , 2010, Analytica chimica acta.

[13]  Hengchong Shi,et al.  Thickness-Dependent Full-Color Emission Tunability in a Flexible Carbon Dot Ionogel. , 2014, The journal of physical chemistry letters.

[14]  Shuqing Sun,et al.  Preparation of high-quality biocompatible carbon dots by extraction, with new thoughts on the luminescence mechanisms , 2013, Nanotechnology.

[15]  Sheila N. Baker,et al.  Luminescent carbon nanodots: emergent nanolights. , 2010, Angewandte Chemie.

[16]  J. C. D. Silva,et al.  Analytical and bioanalytical applications of carbon dots , 2011 .

[17]  Huzhi Zheng,et al.  Microwave–hydrothermal synthesis of fluorescent carbon dots from graphite oxide , 2011 .

[18]  Mingtao Zheng,et al.  One-step synthesis of amino-functionalized fluorescent carbon nanoparticles by hydrothermal carbonization of chitosan. , 2012, Chemical communications.

[19]  Zhenhui Kang,et al.  Carbon nanodots: synthesis, properties and applications , 2012 .

[20]  Olivier Lazcka,et al.  Pathogen detection: a perspective of traditional methods and biosensors. , 2007, Biosensors & bioelectronics.

[21]  Lan Sheng,et al.  Carbon Dots with Continuously Tunable Full-Color Emission and Their Application in Ratiometric pH Sensing , 2014 .

[22]  Wolfgang J. Parak,et al.  Cellular toxicity of inorganic nanoparticles: Common aspects and guidelines for improved nanotoxicity evaluation , 2011 .

[23]  Haifang Wang,et al.  Fluorescent carbon dots and nanodiamonds for biological imaging: preparation, application, pharmacokinetics and toxicity. , 2012, Current drug metabolism.

[24]  Chuan Yi Tang,et al.  A 2.|E|-Bit Distributed Algorithm for the Directed Euler Trail Problem , 1993, Inf. Process. Lett..

[25]  Fan Yang,et al.  Carbon-based quantum dots for fluorescence imaging of cells and tissues , 2014 .

[26]  Nan Zhang,et al.  Carbon dots based dual-emission silica nanoparticles as a ratiometric nanosensor for Cu(2+). , 2014, Analytical chemistry.

[27]  Liangti Qu,et al.  Nitrogen-doped graphene quantum dots with oxygen-rich functional groups. , 2012, Journal of the American Chemical Society.

[28]  K. Krogfelt,et al.  Direct evidence that the FimH protein is the mannose-specific adhesin of Escherichia coli type 1 fimbriae , 1990, Infection and immunity.

[29]  Phenylboronic acid functionalized gold nanoparticles for highly sensitive detection of Staphylococcus aureus. , 2012, Nanoscale.

[30]  E. Giannelis,et al.  Luminescent Surface Quaternized Carbon Dots , 2012 .

[31]  Chih-Ching Huang,et al.  Synthesis of fluorescent carbohydrate-protected Au nanodots for detection of Concanavalin A and Escherichia coli. , 2009, Analytical chemistry.

[32]  M. Los,et al.  Antibody modified gold nanoparticles for fast and selective, colorimetric T7 bacteriophage detection. , 2014, Bioconjugate chemistry.

[33]  Nuo Duan,et al.  A dual-color flow cytometry protocol for the simultaneous detection of Vibrio parahaemolyticus and Salmonella typhimurium using aptamer conjugated quantum dots as labels. , 2013, Analytica chimica acta.

[34]  Hao Wang,et al.  One-step microwave-assisted polyol synthesis of green luminescent carbon dots as optical nanoprobes , 2014 .

[35]  Ya‐Ping Sun,et al.  Versatility with carbon dots – from overcooked BBQ to brightly fluorescent agents and photocatalysts , 2013 .

[36]  E. Giannelis,et al.  Formation mechanism of carbogenic nanoparticles with dual photoluminescence emission. , 2012, Journal of the American Chemical Society.

[37]  C. Davis.  Enumeration of probiotic strains: Review of culture-dependent and alternative techniques to quantify viable bacteria. , 2014, Journal of microbiological methods.

[38]  Ewin N. Tang,et al.  In vivo imaging of infection using a bacteria-targeting optical nanoprobe. , 2014, Journal of biomedical nanotechnology.

[39]  Hua He,et al.  Microwave-assisted one-step green synthesis of amino-functionalized fluorescent carbon nitride dots from chitosan. , 2013, Luminescence : the journal of biological and chemical luminescence.

[40]  Jun‐Jie Zhu,et al.  Quantum dots for fluorescent biosensing and bio-imaging applications. , 2013, The Analyst.

[41]  R. Zbořil,et al.  Surfactant-Derived Amphiphilic Carbon Dots with Tunable Photoluminescence , 2013 .

[42]  Guonan Chen,et al.  Blue luminescent graphene quantum dots and graphene oxide prepared by tuning the carbonization degree of citric acid , 2012 .

[43]  Erkang Wang,et al.  Metal nanoclusters: New fluorescent probes for sensors and bioimaging , 2014 .

[44]  Reinhard Niessner,et al.  Review: bioanalytical applications of biomolecule-functionalized nanometer-sized doped silica particles. , 2009, Analytica chimica acta.

[45]  C. M. Li,et al.  Carbon-based dots co-doped with nitrogen and sulfur for high quantum yield and excitation-independent emission. , 2013, Angewandte Chemie.

[46]  Xiaoling Yang,et al.  Photoluminescence enhancement of carbon dots by gold nanoparticles conjugated via PAMAM dendrimers. , 2013, Nanoscale.

[47]  Bai Yang,et al.  Common origin of green luminescence in carbon nanodots and graphene quantum dots. , 2014, ACS nano.

[48]  B. Lee,et al.  Versatile surface plasmon resonance of carbon-dot-supported silver nanoparticles in polymer optoelectronic devices , 2013, Nature Photonics.

[49]  T. K. Maiti,et al.  Simple one-step synthesis of highly luminescent carbon dots from orange juice: application as excellent bio-imaging agents. , 2012, Chemical communications.

[50]  David Issadore,et al.  Ubiquitous detection of gram-positive bacteria with bioorthogonal magnetofluorescent nanoparticles. , 2011, ACS nano.

[51]  Probal Banerjee,et al.  Magnetic iron oxide-fluorescent carbon dots integrated nanoparticles for dual-modal imaging, near-infrared light-responsive drug carrier and photothermal therapy. , 2014, Biomaterials science.

[52]  Ya‐Ping Sun,et al.  Quantum-sized carbon dots for bright and colorful photoluminescence. , 2006, Journal of the American Chemical Society.