scholarly journals Finding Value in Wastewaters from the Cork Industry: Carbon Dots Synthesis and Fluorescence for Hemeprotein Detection

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2320
Author(s):  
Marta R. Alexandre ◽  
Alexandra I. Costa ◽  
Mário N. Berberan-Santos ◽  
José V. Prata
Keyword(s):  
Cytochrome C ◽  
Carbon Dots ◽  
Carbon Nanomaterials ◽  
Direct Detection ◽  
Photophysical Properties ◽  
Industrial Effluent ◽  
Protein Detection ◽  
Fluorescence Probes ◽  
Collisional Quenching ◽  
Cork Industry

Valorisation of industrial low-value waste residues was preconized. Hence, carbon dots (C-dots) were synthesized from wastewaters of the cork industry—an abundant and affordable, but environmentally-problematic industrial effluent. The carbon nanomaterials were structurally and morphologically characterised, and their photophysical properties were analysed by an ensemble of spectroscopy techniques. Afterwards, they were successfully applied as highly-sensitive fluorescence probes for the direct detection of haemproteins. Haemoglobin, cytochrome c and myoglobin were selected as specific targets owing to their relevant roles in living organisms, wherein their deficiencies or surpluses are associated with several medical conditions. For all of them, remarkable responses were achieved, allowing their detection at nanomolar levels. Steady-state and time-resolved fluorescence, ground-state UV–Vis absorption and electronic circular dichroism techniques were used to investigate the probable mechanisms behind the fluorescence turn-off of C-dots. Extensive experimental evidence points to a static quenching mechanism. Likewise, resonance energy transfer and collisional quenching have been discarded as excited-state deactivating mechanisms. It was additionally found that an oxidative, photoinduced electron transfer occurs for cytochrome c, the most electron-deficient protein. Besides, C-dots prepared from citric acid/ethylenediamine were comparatively assayed for protein detection and the differences between the two types of nanomaterials highlighted.

scholarly journals Universal amplification-free molecular diagnostics by billion-fold hierarchical nanofluidic concentration

2019 ◽  
Vol 116 (33) ◽  
pp. 16240-16249 ◽  
Author(s):  
Wei Ouyang ◽  
Jongyoon Han
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Molecular Diagnostics ◽  
Troponin I ◽  
Direct Detection ◽  
Signal To Noise Ratio ◽  
Protein Detection ◽  
Clinical Diagnostics ◽  
Nucleic Acid Amplification ◽  
Enzyme Linked Immunosorbent Assay

Rapid and reliable detection of ultralow-abundance nucleic acids and proteins in complex biological media may greatly advance clinical diagnostics and biotechnology development. Currently, nucleic acid tests rely on enzymatic processes for target amplification (e.g., PCR), which have many inherent issues restricting their implementation in diagnostics. On the other hand, there exist no protein amplification techniques, greatly limiting the development of protein-based diagnosis. We report a universal biomolecule enrichment technique termed hierarchical nanofluidic molecular enrichment system (HOLMES) for amplification-free molecular diagnostics using massively paralleled and hierarchically cascaded nanofluidic concentrators. HOLMES achieves billion-fold enrichment of both nucleic acids and proteins within 30 min, which not only overcomes many inherent issues of nucleic acid amplification but also provides unprecedented enrichment performance for protein analysis. HOLMES features the ability to selectively enrich target biomolecules and simultaneously deplete nontargets directly in complex crude samples, thereby enormously enhancing the signal-to-noise ratio of detection. We demonstrate the direct detection of attomolar nucleic acids in urine and serum within 35 min and HIV p24 protein in serum within 60 min. The performance of HOLMES is comparable to that of nucleic acid amplification tests and near million-fold improvement over standard enzyme-linked immunosorbent assay (ELISA) for protein detection, being much simpler and faster in both applications. We additionally measured human cardiac troponin I protein in 9 human plasma samples, and showed excellent agreement with ELISA and detection below the limit of ELISA. HOLMES is in an unparalleled position to unleash the potential of protein-based diagnosis.

scholarly journals Hydrogen Bond Acceptors and Additional Cationic Charges in Methylene Blue Derivatives: Photophysics and Antimicrobial Efficiency

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Ariane Felgenträger ◽  
Tim Maisch ◽  
Daniel Dobler ◽  
Andreas Späth
Keyword(s):  
Methylene Blue ◽  
Singlet Oxygen ◽  
Direct Detection ◽  
Photophysical Properties ◽  
Red Light ◽  
Quantum Yields ◽  
Antimicrobial Efficiency ◽  
Highly Active ◽  
Light Region ◽  
Multiresistant Bacteria

Photodynamic inactivation of bacteria (PIB) by efficient singlet oxygen photosensitizers might be a beneficial alternative to antibiotics in the struggle against multiresistant bacteria. Phenothiazinium dyes belong to the most prominent classes of such sensitizers due to their intense absorption in the red-light region ( ca. 600–680 nm,  L mol−1 cm−1), their low toxicity, and their attachment/penetration abilities. Except simple substituents like alkyl or hydroxyalkyl residues, nearly no modifications of the phenothiaziniums have been pursued at the auxochromic sites. By this, the properties of methylene blue derivatives and their fields of application are limited; it remains unclear if their potential antimicrobial efficacy may be enhanced, also to compete with porphyrins. We prepared a set of six mainly novel methylene blue derivatives with the ability of additional hydrogen bonding and/or additional cationic charges to study the substituents’ effect on their activity/toxicity profiles and photophysical properties. Direct detection of singlet oxygen was performed at 1270 nm and the singlet oxygen quantum yields were determined. In suspensions with both, Gram-positive and Gram-negative bacteria, some derivatives were highly active upon illumination to inactivateS. aureusandE. coliup to 7 log10steps (99.99999%) without inherent toxicities in the nonirradiated state.

ChemInform Abstract: Carbon Dots: The Newest Member of the Carbon Nanomaterials Family

ChemInform ◽  
2015 ◽  
Vol 46 (33) ◽  
pp. no-no
Author(s):  
A. L. Himaja ◽  
P. S. Karthik ◽  
Surya Prakash Singh
Keyword(s):  
Carbon Dots ◽  
Carbon Nanomaterials

Host–guest carbon dots as high-performance fluorescence probes

2017 ◽  
Vol 5 (25) ◽  
pp. 6328-6335 ◽  
Author(s):  
Ping Wang ◽  
Jia-Hui Liu ◽  
Haidi Gao ◽  
Yin Hu ◽  
Xiaofang Hou ◽  
...  
Keyword(s):  
Carbon Dots ◽  
High Performance ◽  
Research Field ◽  
Hybrid Nanostructures ◽  
Fluorescence Probes

Host–guest carbon dots (G@CDots) represent a new platform in the rapidly advancing and expanding research field of carbon dots, enabling the development of novel carbon hybrid nanostructures of unique properties beyond those of conventional carbon dots.

scholarly journals A switchable peroxidase mimic derived from the reversible co-assembly of cytochrome c and carbon dots

2016 ◽  
Vol 4 (12) ◽  
pp. 2163-2170 ◽  
Author(s):  
Jeremy B. Essner ◽  
Richard N. McCay ◽  
Chip J. Smith II ◽  
Stephen M. Cobb ◽  
Charles H. Laber ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Carbon Dots ◽  
Heme Protein ◽  
Peroxidase Mimic ◽  
Electrostatic Assembly

We describe a straightforward tactic to boost the inherently low peroxidase-like activity of the heme-protein equine cytochrome c following its electrostatic assembly onto the carbon nanodot surface.

scholarly journals Role of tau protein on the photophysical properties of fluorescent carbon dots

2021 ◽  
Vol 17 (S2) ◽  
Author(s):  
Nayomi S Camilus ◽  
Sarah Lucas ◽  
Colin Wu ◽  
Rafik Naccache ◽  
Sanela Martic
Keyword(s):  
Tau Protein ◽  
Carbon Dots ◽  
Photophysical Properties ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

scholarly journals High‐Performance Red/Near‐IR Carbon Dots as Fluorescence Probes for Tumor Imaging In Vivo

2018 ◽  
Vol 3 (23) ◽  
pp. 6374-6381 ◽  
Author(s):  
Sheng‐Tao Yang ◽  
Jia‐Hui Liu ◽  
Ping Wang ◽  
Shengnan Yang ◽  
Lin Ge ◽  
...  
Keyword(s):  
Carbon Dots ◽  
High Performance ◽  
Tumor Imaging ◽  
Fluorescence Probes ◽  
Near Ir

scholarly journals Photoluminescent Nanomaterials for Medical Biotechnology

Acta Naturae ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 16-31
Author(s):  
Evgenii L. Guryev ◽  
Samah Shanwar ◽  
Andrei Vasilevich Zvyagin ◽  
Sergey M. Deyev ◽  
Irina V. Balalaeva
Keyword(s):  
Quantum Dots ◽  
Porous Silicon ◽  
Sensitivity And Specificity ◽  
Carbon Dots ◽  
Photophysical Properties ◽  
Gold Nanoclusters ◽  
Semiconductor Quantum Dots ◽  
Diagnostic Methods ◽  
Optical Diagnostic ◽  
Therapy Effectiveness

Creation of various photoluminescent nanomaterials has significantly expanded the arsenal of approaches used in modern biomedicine. Their unique photophysical properties can significantly improve the sensitivity and specificity of diagnostic methods, increase therapy effectiveness, and make a theranostic approach to treatment possible through the application of nanoparticle conjugates with functional macromolecules. The most widely used nanomaterials to date are semiconductor quantum dots; gold nanoclusters; carbon dots; nanodiamonds; semiconductor porous silicon; and up-conversion nanoparticles. This paper considers the promising groups of photoluminescent nanomaterials that can be used in medical biotechnology: in particular, for devising agents for optical diagnostic methods, sensorics, and various types of therapy.

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