Sensors

10 pages, 3238 KiB

Open AccessArticle

A Biocompatible Colorimetric Triphenylamine- Dicyanovinyl Conjugated Fluorescent Probe for Selective and Sensitive Detection of Cyanide Ion in Aqueous Media and Living Cells

by Zi-Hua Zheng^1,2, Zhi-Ke Li³, Lin-Jiang Song³, Qi-Wei Wang¹, Qing-Fei Huang^1,* and Li Yang^3,*

¹ Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China

² University of Chinese Academy of Sciences, Beijing 100049, China

³ Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610041, China

Sensors 2017, 17(2), 405; https://doi.org/10.3390/s17020405 - 19 Feb 2017

Cited by 12 | Viewed by 8670

Abstract

A colorimetric and turn-on fluorescent probe 1 bearing triphenylamine-thiophene and dicyanovinyl groups has been synthesized and used to detect cyanide anion via a nucleophilic addition reaction. Probe 1 exhibited prominent selectivity and sensitivity towards CN⁻ in aqueous media, even in the presence [...] Read more.

A colorimetric and turn-on fluorescent probe 1 bearing triphenylamine-thiophene and dicyanovinyl groups has been synthesized and used to detect cyanide anion via a nucleophilic addition reaction. Probe 1 exhibited prominent selectivity and sensitivity towards CN⁻ in aqueous media, even in the presence of other anions such as S²⁻, HS⁻, SO₃²⁻, S₂O₃²⁻, S₂O₈²⁻, I⁻, Br⁻, Cl⁻, F⁻, NO₂⁻, N₃⁻, SO₄²⁻, SCN⁻, HCO₃⁻, CO₃²⁻ and AcO⁻. Moreover, a low detection limit (LOD, 51 nM) was observed. In addition, good cell membrane permeability and low cytotoxicity to HeLa cells were also observed, suggesting its promising potential in bio-imaging. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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12 pages, 7034 KiB

Open AccessArticle

Hierarchical NiCo₂O₄ Hollow Sphere as a Peroxidase Mimetic for Colorimetric Detection of H₂O₂ and Glucose

by Wei Huang¹, Tianye Lin¹, Yang Cao¹, Xiaoyong Lai², Juan Peng² and Jinchun Tu^1,*

¹ State Key Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Tropical Biological Resources of Ministry of Education Hainan University, College of Material and Chemical Engineering, Haikou 570228, China

² Laboratory Cultivation Base of Natural Gas Conversion, School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China

Sensors 2017, 17(1), 217; https://doi.org/10.3390/s17010217 - 23 Jan 2017

Cited by 43 | Viewed by 10070

Abstract

In this work, the hierarchical NiCo₂O₄ hollow sphere synthesized via a “coordinating etching and precipitating” process was demonstrated to exhibit intrinsic peroxidase-like activity. The peroxidase-like activity of NiCo₂O₄, NiO, and Co₃O₄ hollow spheres [...] Read more.

In this work, the hierarchical NiCo₂O₄ hollow sphere synthesized via a “coordinating etching and precipitating” process was demonstrated to exhibit intrinsic peroxidase-like activity. The peroxidase-like activity of NiCo₂O₄, NiO, and Co₃O₄ hollow spheres were comparatively studied by the catalytic oxidation reaction of 3,3,5,5-tetramethylbenzidine (TMB) in presence of H₂O₂, and a superior peroxidase-like activity of NiCo₂O₄ was confirmed by stronger absorbance at 652 nm. Furthermore, the proposed sensing platform showed commendable response to H₂O₂ with a linear range from 10 μM to 400 μM, and a detection limit of 0.21 μM. Cooperated with GOx, the developed novel colorimetric and visual glucose-sensing platform exhibited high selectivity, favorable reproducibility, satisfactory applicability, wide linear range (from 0.1 mM to 4.5 mM), and a low detection limit of 5.31 μM. In addition, the concentration-dependent color change would offer a better and handier way for detection of H₂O₂ and glucose by naked eye. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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10 pages, 1950 KiB

Open AccessArticle

Detection of the Vascular Endothelial Growth Factor with a Novel Bioluminescence Resonance Energy Transfer Pair Using a Two-Component System

by Tobias Wimmer, Eva Schroeter, Birgit Lorenz and Knut Stieger^*

Department of Ophthalmology, Justus-Liebig-University Giessen, Friedrichstr. 18, 35390 Giessen, Germany

Sensors 2017, 17(1), 145; https://doi.org/10.3390/s17010145 - 13 Jan 2017

Cited by 6 | Viewed by 5479

Abstract

In this paper we describe a two-component BRET (bioluminescence resonance energy transfer)-based method to detect vascular endothelial growth factor (VEGF) molecules in unknown samples as the basis for subsequent in vivo use. A luminescent VEGF binding molecule, which binds in the receptor binding [...] Read more.

In this paper we describe a two-component BRET (bioluminescence resonance energy transfer)-based method to detect vascular endothelial growth factor (VEGF) molecules in unknown samples as the basis for subsequent in vivo use. A luminescent VEGF binding molecule, which binds in the receptor binding motif of VEGF, is used as the energy donor, transferred to a fluorophore-coupled VEGF binding molecule (acceptor), which binds to the neuropilin binding motif of VEGF, thus enabling energy transfer from the donor to the acceptor molecule. This leads to the emission of light at a longer wavelength and thus the generation of an increased BRET signal only when VEGF is bound to both the donor and acceptor molecules. We further describe a novel BRET pair that uses the Renilla reniformis mutant luciferase RLuc8 and the chemically engineered fluorophore PerCP-Cy5.5^®, which exhibits superior peak separation of approximately 300 nm. The implantation of capsules consisting of the two BRET components in solution, permeable for VEGF for its in vivo detection, would provide a new and improved method for monitoring VEGF-induced pathologies and thus an adjustment of therapy to patient needs. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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10 pages, 2940 KiB

Open AccessArticle

Enhancement of Fluorescence-Based Sandwich Immunoassay Using Multilayered Microplates Modified with Plasma-Polymerized Films

by Kazuyoshi Yano^* and Akira Iwasaki

School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo 192-0982, Japan

Sensors 2017, 17(1), 37; https://doi.org/10.3390/s17010037 - 25 Dec 2016

Cited by 7 | Viewed by 5523

Abstract

A functional modification of the surface of a 96-well microplate coupled with a thin layer deposition technique is demonstrated for enhanced fluorescence-based sandwich immunoassays. The plasma polymerization technique enabling the deposition of organic thin films was employed for the modification of the well [...] Read more.

A functional modification of the surface of a 96-well microplate coupled with a thin layer deposition technique is demonstrated for enhanced fluorescence-based sandwich immunoassays. The plasma polymerization technique enabling the deposition of organic thin films was employed for the modification of the well surface of a microplate. A silver layer and a plasma-polymerized film were consecutively deposited on the microplate as a metal mirror and the optical interference layer, respectively. When Cy3-labeled antibody was applied to the wells of the resulting multilayered microplate without any immobilization step, greatly enhanced fluorescence was observed compared with that obtained with the unmodified one. The same effect could be also exhibited for an immunoassay targeting antigen directly adsorbed on the multilayered microplate. Furthermore, a sandwich immunoassay for the detection of interleukin 2 (IL-2) was performed with the multilayered microplates, resulting in specific and 88-fold–enhanced fluorescence detection. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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8 pages, 823 KiB

Open AccessArticle

A Cu²⁺-Selective Probe Based on Phenanthro-Imidazole Derivative

by Dandan Cheng^1,†, Xingliang Liu^1,†, Hongzhi Yang¹, Tian Zhang², Aixia Han^1,* and Ling Zang^3,*

¹ Chemical Engineering College, Qinghai University, Xining 810016, China

² Qinghai Heavy Industry Vocational School, Xining 810101, China

³ Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112, USA

^† These two authors contributed equally.

Sensors 2017, 17(1), 35; https://doi.org/10.3390/s17010035 - 24 Dec 2016

Cited by 28 | Viewed by 7456

Abstract

A novel fluorescent Probe 1, based on phenanthro-imidazole has been developed as an efficient chemosensor for the trace detection of copper ions (Cu²⁺). Probe 1 demonstrated sensitive fluorescence quenching upon binding with Cu²⁺ through 1:1 stoichiometric chelation. The detection [...] Read more.

A novel fluorescent Probe 1, based on phenanthro-imidazole has been developed as an efficient chemosensor for the trace detection of copper ions (Cu²⁺). Probe 1 demonstrated sensitive fluorescence quenching upon binding with Cu²⁺ through 1:1 stoichiometric chelation. The detection limit for Cu²⁺ ions was projected through linear quenching fitting to be as low as 2.77 × 10⁻⁸ M (or 1.77 ppb). The sensing response was highly selective towards Cu²⁺ with minimal influence from other common metal ions, facilitating the practical application of Probe 1 in trace detection. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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12 pages, 2603 KiB

Open AccessArticle

Visualization of Fluoride Ions In Vivo Using a Gadolinium(III)-Coumarin Complex-Based Fluorescence/MRI Dual-Modal Probe

by Yue Wang¹, Renfeng Song², Huan Feng¹, Ke Guo², Qingtao Meng^1,*, Haijun Chi¹, Run Zhang^1,3,* and Zhiqiang Zhang¹

¹ School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, China

² Ansteel Mining Engineering Corporation, Anshan 114002, China

³ Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane 4072, Australia

Sensors 2016, 16(12), 2165; https://doi.org/10.3390/s16122165 - 16 Dec 2016

Cited by 13 | Viewed by 7706

Abstract

A new Gadolinium(III)–coumarin complex, DO3A-Gd-CA, was designed and prepared as a dual-modal probe for simultaneous fluorescence and relaxivity responses to fluoride ions (F⁻) in aqueous media and mice. DO3A-Gd-CA was designed by using Gd(III) center as an MRI [...] Read more.

A new Gadolinium(III)–coumarin complex, DO3A-Gd-CA, was designed and prepared as a dual-modal probe for simultaneous fluorescence and relaxivity responses to fluoride ions (F⁻) in aqueous media and mice. DO3A-Gd-CA was designed by using Gd(III) center as an MRI signal output unit and fluoride binding site, and the 4-(diethylamino)-coumarin-3-carboxylic acid (CA) as a fluorescence reporter. Upon the addition of fluoride ions to the solution of DO3A-Gd-CA, the liberation of the coordinated CA ligand led to a 5.7-fold fluorescence enhancement and a 75% increase in the longitudinal relaxivity (r₁). The fluorescent detection limit for fluoride ions was determined to be 8 μM based on a 3σ/slope. The desirable features of the proposed DO3A-Gd-CA, such as high sensitivity and specificity, reliability at physiological pH and low cytotoxicity enable its application in visualization of fluoride ion in mice. The successful in vivo imaging indicates that DO3A-Gd-CA could be potentially used in biomedical diagnosis fields. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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11 pages, 1931 KiB

Open AccessArticle

An Ionic 1,4-Bis(styryl)benzene-Based Fluorescent Probe for Mercury(II) Detection in Water via Deprotection of the Thioacetal Group

by Van Sang Le¹, Ji-Eun Jeong², Huy Tuan Huynh¹, Jiae Lee² and Han Young Woo^2,*

¹ Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Korea

² Department of Chemistry, Korea University, Seoul 02841, Korea

Sensors 2016, 16(12), 2082; https://doi.org/10.3390/s16122082 - 7 Dec 2016

Cited by 8 | Viewed by 6810

Abstract

Highly sensitive and selective mercury detection in aqueous media is urgently needed because mercury poisoning usually results from exposure to water-soluble forms of mercury by inhalation and/or ingesting. An ionic conjugated oligoelectrolye (M1Q) based on 1,4-bis(styryl)benzene was synthesized as a fluorescent mercury(II) probe. [...] Read more.

Highly sensitive and selective mercury detection in aqueous media is urgently needed because mercury poisoning usually results from exposure to water-soluble forms of mercury by inhalation and/or ingesting. An ionic conjugated oligoelectrolye (M1Q) based on 1,4-bis(styryl)benzene was synthesized as a fluorescent mercury(II) probe. The thioacetal moiety and quaternized ammonium group were incorporated for Hg²⁺ recognition and water solubility. A neutral Hg²⁺ probe (M1) was also prepared based on the same molecular backbone, and their sensor characteristics were investigated in a mixture of acetonitrile/water and in water. In the presence of Hg²⁺, the thioacetal group was converted to aldehyde functionality, and the resulting photoluminescence intensity decreased. In water, M1Q successfully demonstrated highly sensitive detection, showing a binding toward Hg²⁺ that was ~15 times stronger and a signal on/off ratio twice as high, compared to M1 in acetonitrile/water. The thioacetal deprotection by Hg²⁺ ions was substantially facilitated in water without an organic cosolvent. The limit of detection was measured to be 7 nM with a detection range of 10–180 nM in 100% aqueous medium. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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10 pages, 1364 KiB

Open AccessArticle

Detection of Ciprofloxacin in Urine through Sensitized Lanthanide Luminescence

by Subhankar Singha

and Kyo Han Ahn^*

Department of Chemistry, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea

Sensors 2016, 16(12), 2065; https://doi.org/10.3390/s16122065 - 5 Dec 2016

Cited by 42 | Viewed by 8588

Abstract

Ciprofloxacin, a fluoroquinolone antibiotic, is widely used for the treatment of bacterial infection in humans due to its broad antibacterial spectrum. An excessive use or overdose of ciprofloxacin on the other hand can cause several adverse effects not only to humans but also [...] Read more.

Ciprofloxacin, a fluoroquinolone antibiotic, is widely used for the treatment of bacterial infection in humans due to its broad antibacterial spectrum. An excessive use or overdose of ciprofloxacin on the other hand can cause several adverse effects not only to humans but also to microorganisms. Unabsorbed ciprofloxacin in the body is mostly excreted through urine and finally goes to the environment, providing a drug resistance pressure on bacteria. Hence a simple and efficient detection method of ciprofloxacin is necessary, which, for example, can be used to analyze ciprofloxacin content in urine. Although ciprofloxacin itself shows inherent fluorescence, direct fluorescent detection of ciprofloxacin in raw urine sample is difficult due to autofluorescence of urine by other components. Herein we report that a Tb(III) complex of DO3A (1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid) can be efficiently sensitized by ciprofloxacin to emit luminescence separately from the urine autofluorescence wavelength region. Tb-DO3A shows excellent sensitivity with a detection limit of three parts per billion in aqueous buffer solution. Further, Tb-DO3A is used to detect ciprofloxacin with high sensitivity and selectivity in a raw urine sample without any purification or separation procedures in the concentrations ranging from 1 µg·mL⁻¹ to 50 µg·mL⁻¹. The direct measurement of ciprofloxacin excreted in urine may be used to control overdose of the drug. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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23 pages, 6993 KiB

Open AccessReview

Integrating Deoxyribozymes into Colorimetric Sensing Platforms

by Dingran Chang¹, Sandy Zakaria², Mimi Deng¹

, Nicholas Allen¹, Kha Tram¹ and Yingfu Li^1,2,*

¹ Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada

² Department of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4K1, Canada

Sensors 2016, 16(12), 2061; https://doi.org/10.3390/s16122061 - 3 Dec 2016

Cited by 41 | Viewed by 9955

Abstract

Biosensors are analytical devices that have found a variety of applications in medical diagnostics, food quality control, environmental monitoring and biodefense. In recent years, functional nucleic acids, such as aptamers and nucleic acid enzymes, have shown great potential in biosensor development due to [...] Read more.

Biosensors are analytical devices that have found a variety of applications in medical diagnostics, food quality control, environmental monitoring and biodefense. In recent years, functional nucleic acids, such as aptamers and nucleic acid enzymes, have shown great potential in biosensor development due to their excellent ability in target recognition and catalysis. Deoxyribozymes (or DNAzymes) are single-stranded DNA molecules with catalytic activity and can be isolated to recognize a wide range of analytes through the process of in vitro selection. By using various signal transduction mechanisms, DNAzymes can be engineered into fluorescent, colorimetric, electrochemical and chemiluminescent biosensors. Among them, colorimetric sensors represent an attractive option as the signal can be easily detected by the naked eye. This reduces reliance on complex and expensive equipment. In this review, we will discuss the recent progress in the development of colorimetric biosensors that make use of DNAzymes and the prospect of employing these sensors in a range of chemical and biological applications. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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15 pages, 3567 KiB

Open AccessArticle

A Multi-Pumping Flow System for In Situ Measurements of Dissolved Manganese in Aquatic Systems

by David Meyer^*, Ralf D. Prien

, Olaf Dellwig, Joanna J. Waniek, Ingo Schuffenhauer, Jan Donath, Siegfried Krüger, Malte Pallentin and Detlef E. Schulz-Bull

Leibniz Institute for Baltic Sea Research Warnemünde, Seestr. 15, 18119 Rostock, Germany

Sensors 2016, 16(12), 2027; https://doi.org/10.3390/s16122027 - 30 Nov 2016

Cited by 11 | Viewed by 6049

Abstract

A METals In Situ analyzer (METIS) has been used to determine dissolved manganese (II) concentrations in the subhalocline waters of the Gotland Deep (central Baltic Sea). High-resolution in situ measurements of total dissolved Mn were obtained in near real-time by spectrophotometry using 1-(2-pyridylazo)-2-naphthol [...] Read more.

A METals In Situ analyzer (METIS) has been used to determine dissolved manganese (II) concentrations in the subhalocline waters of the Gotland Deep (central Baltic Sea). High-resolution in situ measurements of total dissolved Mn were obtained in near real-time by spectrophotometry using 1-(2-pyridylazo)-2-naphthol (PAN). PAN is a complexing agent of dissolved Mn and forms a wine-red complex with a maximum absorbance at a wavelength of 562 nm. Results are presented together with ancillary temperature, salinity, and dissolved O

_{2}

data. Lab calibration of the analyzer was performed in a pressure testing tank. A detection limit of 77 nM was obtained. For validation purposes, discrete water samples were taken by using a pump-CTD system. Dissolved Mn in these samples was determined by an independent laboratory based method (inductively coupled plasma–optical emission spectrometry, ICP-OES). Mn measurements from both METIS and ICP-OES analysis were in good agreement. The results showed that the in situ analysis of dissolved Mn is a powerful technique reducing dependencies on heavy and expensive equipment (pump-CTD system, ICP-OES) and is also cost and time effective. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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9 pages, 3076 KiB

Open AccessArticle

One-Pot Click Access to a Cyclodextrin Dimer-Based Novel Aggregation Induced Emission Sensor and Monomer-Based Chiral Stationary Phase

by Xiaoli Li^1,2, Rui Zhao^1,2, Xiaoying Tang^1,2, Yanyan Shi^1,2, Chunyi Li² and Yong Wang^1,2,*

¹ Tianjin Key Laboratory of Molecular Optoelectronic Science, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China

² Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China

Sensors 2016, 16(12), 1985; https://doi.org/10.3390/s16121985 - 24 Nov 2016

Cited by 8 | Viewed by 8234

Abstract

A ‘two birds, one stone’ strategy was developed via a one-pot click reaction to simultaneously prepare a novel cyclodextrin (CD) dimer based aggregation induced emission (AIE) sensor (AIE-DCD) and a monomer based chiral stationary phase (CSP-MCD) for chiral high performance liquid chromatography (CHPLC). [...] Read more.

A ‘two birds, one stone’ strategy was developed via a one-pot click reaction to simultaneously prepare a novel cyclodextrin (CD) dimer based aggregation induced emission (AIE) sensor (AIE-DCD) and a monomer based chiral stationary phase (CSP-MCD) for chiral high performance liquid chromatography (CHPLC). AIE-DCD was found to afford satisfactory AIE response for specific detection of Zn²⁺ with a detection limit of 50 nM. CSP-MCD exhibits excellent enantioseparation ability toward dansyl amino acids, where the resolution of dansyl amino leucine reaches 5.43. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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10 pages, 1620 KiB

Open AccessArticle

Label-Free Fluorescent Detection of Trypsin Activity Based on DNA-Stabilized Silver Nanocluster-Peptide Conjugates

by Cai-Xia Zhuo^1,2,†, Li-Hui Wang^1,2,†, Jing-Jing Feng^1,2 and Yao-Dong Zhang^1,2,*,†

¹ Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, China

² Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, China

^† These authors contributed equally to this work.

Sensors 2016, 16(11), 1477; https://doi.org/10.3390/s16111477 - 9 Nov 2016

Cited by 19 | Viewed by 8667

Abstract

Trypsin is important during the regulation of pancreatic exocrine function. The detection of trypsin activity is currently limited because of the need for the substrate to be labeled with a fluorescent tag. A label-free fluorescent method has been developed to monitor trypsin activity. [...] Read more.

Trypsin is important during the regulation of pancreatic exocrine function. The detection of trypsin activity is currently limited because of the need for the substrate to be labeled with a fluorescent tag. A label-free fluorescent method has been developed to monitor trypsin activity. The designed peptide probe consists of six arginine molecules and a cysteine terminus and can be conjugated to DNA-stabilized silver nanoclusters (DNA-AgNCs) by Ag-S bonding to enhance fluorescence. The peptide probe can also be adsorbed to the surface of graphene oxide (GO), thus resulting in the fluorescence quenching of DNA-AgNCs-peptide conjugate because of Förster resonance energy transfer. Once trypsin had degraded the peptide probe into amino acid residues, the DNA-AgNCs were released from the surface of GO, and the enhanced fluorescence of DNA-AgNCs was restored. Trypsin can be determined with a linear range of 0.0–50.0 ng/mL with a concentration as low as 1 ng/mL. This label-free method is simple and sensitive and has been successfully used for the determination of trypsin in serum. The method can also be modified to detect other proteases. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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11 pages, 2837 KiB

Open AccessArticle

Detection of Copper(II) Ions Using Glycine on Hydrazine-Adsorbed Gold Nanoparticles via Raman Spectroscopy

by Nguyễn Hoàng Ly¹

, Chulhun Seo² and Sang-Woo Joo^1,2,*

¹ Department of Chemistry, Soongsil University, Seoul 156-743, Korea

² Department of Information Communication, Materials, and Chemistry Convergence Technology, Soongsil University, Seoul 156-743, Korea

Sensors 2016, 16(11), 1785; https://doi.org/10.3390/s16111785 - 26 Oct 2016

Cited by 30 | Viewed by 9414

Abstract

A facile, selective, and sensitive detection method for the Cu²⁺ ions in environmental and biological solutions has been newly developed by observing the unique CN stretching peaks at ~2108 cm⁻¹ upon the dissociative adsorption of glycine (GLY) in hydrazine buffer on [...] Read more.

A facile, selective, and sensitive detection method for the Cu²⁺ ions in environmental and biological solutions has been newly developed by observing the unique CN stretching peaks at ~2108 cm⁻¹ upon the dissociative adsorption of glycine (GLY) in hydrazine buffer on gold nanoparticles (AuNPs). The relative abundance of Cu species on AuNPs was identified from X-ray photoelectron spectroscopy analysis. UV-Vis spectra also indicated that the Au particles aggregated to result in the color change owing to the destabilization induced by the GLY-Cu²⁺ complex. The CN stretching band at ~2108 cm⁻¹ could be observed to indicate the formation of the CN species from GLY on the hydrazine-covered AuNP surfaces. The other ions of Fe³⁺, Fe²⁺, Hg²⁺, Mg²⁺, Mn²⁺, Ni²⁺, Zn²⁺, Cr³⁺, Co²⁺, Cd²⁺, Pb²⁺, Ca²⁺, NH₄⁺, Na⁺, and K⁺ at high concentrations of 50 µM did not produce such spectral changes. The detection limit based on the CN band for the determination of the Cu²⁺ ion could be estimated to be as low as 500 nM in distilled water and 1 µM in river water, respectively. We attempted to apply our method to estimate intracellular ion detection in cancer cells for more practical purposes. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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8 pages, 980 KiB

Open AccessArticle

ESIPT-Based Photoactivatable Fluorescent Probe for Ratiometric Spatiotemporal Bioimaging

by Xiaohong Zhou^1,2, Yuren Jiang^1,*, Xiongjie Zhao¹ and Dong Guo¹

¹ College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China

² Environment Monitoring Department, Changsha Environmental Protection College, Changsha 410004, China

Sensors 2016, 16(10), 1684; https://doi.org/10.3390/s16101684 - 12 Oct 2016

Cited by 9 | Viewed by 7321

Abstract

Photoactivatable fluorophores have become an important technique for the high spatiotemporal resolution of biological imaging. Here, we developed a novel photoactivatable probe (PHBT), which is based on 2-(2-hydroxyphenyl)benzothiazole (HBT), a small organic fluorophore known for its classic luminescence mechanism through excited-state intramolecular proton [...] Read more.

Photoactivatable fluorophores have become an important technique for the high spatiotemporal resolution of biological imaging. Here, we developed a novel photoactivatable probe (PHBT), which is based on 2-(2-hydroxyphenyl)benzothiazole (HBT), a small organic fluorophore known for its classic luminescence mechanism through excited-state intramolecular proton transfer (ESIPT) with the keto form and the enol form. After photocleavage, PHBT released a ratiometric fluorophore HBT, which showed dual emission bands with more than 73-fold fluorescence enhancement at 512 nm in buffer and more than 69-fold enhancement at 452 nm in bovine serum. The probe displayed a high ratiometric imaging resolution and is believed to have a wide application in biological imaging. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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12 pages, 2329 KiB

Open AccessArticle

Highly Selective and Ultrasensitive Turn-on Luminescence Chemosensor for Mercury (II) Determination Based on the Rhodamine 6G Derivative FC1 and Au Nanoparticles

by Romina Brasca¹, María C. Onaindia¹, Héctor C. Goicoechea¹, Arsenio Muñoz de la Peña^2,* and María J. Culzoni^1,*

¹ Laboratorio de Desarrollo Analítico y Quimiometría (LADAQ), Universidad Nacional del Litoral, CONICET, FBCB, Ciudad Universitaria, Santa Fe 3000, Argentine

² Department of Analytical Chemistry and IACYS, University of Extremadura, Badajoz 06006, Spain

Sensors 2016, 16(10), 1652; https://doi.org/10.3390/s16101652 - 6 Oct 2016

Cited by 8 | Viewed by 5984

Abstract

A method for the detection and quantitation of Hg2+ in aqueous samples by fluorescence spectroscopy is presented. It consists of a turn-on sensor developed by coupling Gold nanoparticles (AuNPs) with the rhodamine 6G derivative FC1, in which the response is generated by a [...] Read more.

A method for the detection and quantitation of Hg2+ in aqueous samples by fluorescence spectroscopy is presented. It consists of a turn-on sensor developed by coupling Gold nanoparticles (AuNPs) with the rhodamine 6G derivative FC1, in which the response is generated by a mercury-induced ring-opening reaction. The AuNPs were included in order to improve the sensitivity of the method towards the analyte, maintaining its high selectivity. The method was validated in terms of linearity, precision and accuracy, and applied to the quantitation of Hg2+ in Milli-Q and tap water with and without spiked analyte. The limit of detection and quantitation were 0.15 μg·L−1 and 0.43 μg·L−1, respectively, constituting a substantial improvement of sensitivity in comparison with the previously reported detection of Hg2+ with free FC1. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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9 pages, 2423 KiB

Open AccessArticle

A Simple BODIPY-Based Viscosity Probe for Imaging of Cellular Viscosity in Live Cells

by Dongdong Su^1,†, Chai Lean Teoh^1,†, Nengyue Gao², Qing-Hua Xu² and Young-Tae Chang^1,2,*

¹ Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), Singapore 138667, Singapore

² Department of Chemistry, National University of Singapore, Singapore 117543, Singapore

Sensors 2016, 16(9), 1397; https://doi.org/10.3390/s16091397 - 31 Aug 2016

Cited by 71 | Viewed by 12673

Abstract

Intracellular viscosity is a fundamental physical parameter that indicates the functioning of cells. In this work, we developed a simple boron-dipyrromethene (BODIPY)-based probe, BTV, for cellular mitochondria viscosity imaging by coupling a simple BODIPY rotor with a mitochondria-targeting unit. The BTV exhibited [...] Read more.

Intracellular viscosity is a fundamental physical parameter that indicates the functioning of cells. In this work, we developed a simple boron-dipyrromethene (BODIPY)-based probe, BTV, for cellular mitochondria viscosity imaging by coupling a simple BODIPY rotor with a mitochondria-targeting unit. The BTV exhibited a significant fluorescence intensity enhancement of more than 100-fold as the solvent viscosity increased. Also, the probe showed a direct linear relationship between the fluorescence lifetime and the media viscosity, which makes it possible to trace the change of the medium viscosity. Furthermore, it was demonstrated that BTV could achieve practical applicability in the monitoring of mitochondrial viscosity changes in live cells through fluorescence lifetime imaging microscopy (FLIM). Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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9 pages, 1005 KiB

Open AccessArticle

Upconversion Nanoparticle-Based Förster Resonance Energy Transfer for Detecting DNA Methylation

by Seockjune Kim¹

, Sang-Hyun Hwang^2,3,*

, Su-Gyeong Im², Min-Ki Lee⁴, Chang-Hun Lee⁵, Sang Jun Son⁶ and Heung-Bum Oh^1,*

¹ Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul 05505, Korea

² Department of Laboratory Medicine, Center for Diagnostic Oncology, Research Institute and Hospital, National Cancer Center, Goyang-si 10408, Korea

³ Hematologic Malignancy Branch, Research Institute and Hospital, National Cancer Center, Goyang-si 10408, Korea

⁴ Department of Internal Medicine, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-ro, Seo-gu, Busan 602-739, Korea

⁵ Department of Pathology, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-ro, Seo-gu, Busan 602-739, Korea

⁶ Department of Chemistry, Gachon University, Seongnam, Gyeonggi, and Gachon Medical Research Institute, Gil Medical Center, Inchon 461-701, Korea

Sensors 2016, 16(8), 1259; https://doi.org/10.3390/s16081259 - 9 Aug 2016

Cited by 14 | Viewed by 6665

Abstract

Aberrant methylation of a crucial CpG island is the main mechanism for the inactivation of CDKN2A in the early stages of carcinogenesis. Therefore, the detection of DNA methylation with high sensitivity and specificity is important, and various detection methods have been developed. Recently, [...] Read more.

Aberrant methylation of a crucial CpG island is the main mechanism for the inactivation of CDKN2A in the early stages of carcinogenesis. Therefore, the detection of DNA methylation with high sensitivity and specificity is important, and various detection methods have been developed. Recently, upconversion nanoparticles (UCNPs) have been found to display a high signal-to-noise ratio and no photobleaching, making them useful for diagnostic applications. In this pilot study, we applied UCNPs to the detection of CDKN2A methylation and evaluated the feasibility of this system for use in molecular diagnostics. DNA PCR was performed using biotinylated primers, and the PCR amplicon was then intercalated with SYTOX Orange dye, followed by incubation with streptavidin-conjugated UCNPs. Fluorescence detection of the Förster resonance energy transfer (FRET) of the UCNPs (MS-UC-FRET) was then performed, and the results were compared to those from real-time PCR (RQ-PCR) and pyrosequencing. Detection by MS-UC-FRET was more sensitive than that by either RQ-PCR or pyrosequencing. Our results confirmed the success of our MS-UC-FRET system for detecting DNA methylation and demonstrated the potential application of this system in molecular diagnostics. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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11 pages, 3176 KiB

Open AccessArticle

Theoretical and Experimental: The Synthetic and Anion-Binding Properties of Tripodal Salicylaldehyde Derivatives

by Zhong-Jie Xu^1,2 and Li-Rong Zhang^1,*

¹ School of Basic Medicine, Zhengzhou University, Zhengzhou 450052, China

² Life Science and Technology College, Xinxiang Medical University, Xinxiang 453003, China

Sensors 2016, 16(5), 733; https://doi.org/10.3390/s16050733 - 19 May 2016

Cited by 4 | Viewed by 5594

Abstract

A series of colorimetric anion probes 1–6 containing OH and NO₂ groups were synthesized, and their recognition properties toward various anions were investigated by visual observation, ultraviolet–visible spectroscopy, fluorescence, ¹H nuclear magnetic resonance titration spectra and theoretical investigation. Nanomaterials of three [...] Read more.

A series of colorimetric anion probes 1–6 containing OH and NO₂ groups were synthesized, and their recognition properties toward various anions were investigated by visual observation, ultraviolet–visible spectroscopy, fluorescence, ¹H nuclear magnetic resonance titration spectra and theoretical investigation. Nanomaterials of three compounds 2–4 were prepared successfully. Four compounds 3–6 that contain electron-withdrawing substituents showed a high binding ability for AcO⁻. The host–guest complex formed through a 1:1 binding ratio, and color changes were detectable during the recognition process. Theoretical investigation analysis revealed that an intramolecular hydrogen bond existed in the structures of compounds and the roles of molecular frontier orbitals in molecular interplay. These studies suggested that this series of compounds could be used as colorimetric probes to detect of AcO⁻. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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12 pages, 3540 KiB

Open AccessArticle

Fluoride Anion Recognition by a Multifunctional Urea Derivative: An Experimental and Theoretical Study

by Jana Schiller¹, Raúl Pérez-Ruiz¹, Diego Sampedro²

, Eugenia Marqués-López³

, Raquel P. Herrera³

and David Díaz Díaz^1,4,*

¹ Institut für Organische Chemie, Universität Regensburg, Universitätsstr. 31, Regensburg 93053, Germany

² Departamento de Química, Universidad de La Rioja, Madre de Dios, 51, Logroño 26006, Spain

³ Laboratorio de Organocatálisis Asimétrica, Departamento de Química Orgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza 50009, Spain

⁴ Instituto de Química Avanzada de Cataluña-Consejo Superior de Investigaciones Científicas (IQAC-CSIC), Jordi Girona 18-26, Barcelona 08034, Spain

Sensors 2016, 16(5), 658; https://doi.org/10.3390/s16050658 - 9 May 2016

Cited by 14 | Viewed by 9180

Abstract

In this work we demonstrate the ability of a multifaceted N,N′-disubstituted urea to selectively recognize fluoride anion (F⁻) among other halides. This additional function is now added to its already reported organocatalytic and organogelator properties. The signaling mechanism [...] Read more.

In this work we demonstrate the ability of a multifaceted N,N′-disubstituted urea to selectively recognize fluoride anion (F⁻) among other halides. This additional function is now added to its already reported organocatalytic and organogelator properties. The signaling mechanism relies on the formation of a charge-transfer (CT) complex between the urea-based sensor and F¯ in the ground state with a high association constant as demonstrated by absorption and fluorescence spectroscopy. The nature of the hydrogen bonding interaction between the sensor and F¯ was established by ¹H-NMR studies and theoretical calculations. Moreover, the recovery of the sensor was achieved by addition of methanol. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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10 pages, 2101 KiB

Open AccessArticle

A Rapid In Situ Colorimetric Assay for Cobalt Detection by the Naked Eye

by Sung-Min Kang^1,2,†, Sung-Chan Jang^1,3,†, Gi Yong Kim^1,2, Chang-Soo Lee^2,*, Yun Suk Huh^3,*

and Changhyun Roh^1,4,*

¹ Biotechnology Research Division, Advanced Radiation Technology Institute (ARTI), Korea Atomic Energy Research Institute (KAERI), 29 Geumgu-gil, Jeongeup, Jeonbuk 56212, Korea

² Department of Chemical Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea

³ Department of Biological Engineering, Biohybrid Systems Research Center (BSRC), Inha University, 100 Inha-ro, Incheon 22212, Korea

⁴ Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology (UST), 217 Gajeong-ro, Daejeon 34113, Korea

^† These authors contributed equally to this work.

Sensors 2016, 16(5), 626; https://doi.org/10.3390/s16050626 - 2 May 2016

Cited by 22 | Viewed by 11351

Abstract

A simple, rapid, and convenient colorimetric chemosensor of a specific target toward the end user is still required for on-site detection and real-time monitoring applications. In this study, we developed a rapid in situ colorimetric assay for cobalt detection using the naked eye. [...] Read more.

A simple, rapid, and convenient colorimetric chemosensor of a specific target toward the end user is still required for on-site detection and real-time monitoring applications. In this study, we developed a rapid in situ colorimetric assay for cobalt detection using the naked eye. Interestingly, a yellow to light orange visual color transition was observed within 3 s when a Chrysoidine G (CG) chemosensor was exposed to cobalt. Surprisingly, the CG chemosensor had great selectivity toward cobalt without any interference of other metal ions. Under optimized conditions, a lower detection limit of 0.1 ppm via a spectrophotometer and a visual detection limit of 2 ppm with a linear range from 0.4 to 1 ppm (R² = 0.97) were determined. Moreover, the CG chemosensor is reversible and maintains its functionality after treatment with chelating agents. In conclusion, we show the superior capabilities of the CG chemosensor, which has the potential to provide extremely facile handling, high sensitivity, and a fast response time for applications of on-site detection to real-time cobalt monitoring for the general public. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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11 pages, 2069 KiB

Open AccessArticle

Optimizing Colorimetric Assay Based on V₂O₅ Nanozymes for Sensitive Detection of H₂O₂ and Glucose

by Jiaheng Sun, Chunyan Li, Yanfei Qi^*, Shuanli Guo and Xue Liang

School of Public Health, Jilin University, Changchun 130021, China

Sensors 2016, 16(4), 584; https://doi.org/10.3390/s16040584 - 22 Apr 2016

Cited by 119 | Viewed by 11554

Abstract

Nanozyme-based chemical sensing is a rapidly emerging field of research. Herein, a simple colorimetric assay for the detection of hydrogen peroxide and glucose based on the peroxidase-like activity of V₂O₅ nanozymes has been established. In this assay, the effects of [...] Read more.

Nanozyme-based chemical sensing is a rapidly emerging field of research. Herein, a simple colorimetric assay for the detection of hydrogen peroxide and glucose based on the peroxidase-like activity of V₂O₅ nanozymes has been established. In this assay, the effects of pH, substrate, nanozyme concentrations and buffer solution have been investigated. It was found that compared with 3,3′,5,5′-tetramethylbenzidine (TMB), the enzyme substrate o-phenylenediamine (OPD) seriously interfered with the H₂O₂ detection. Under the optimal reaction conditions, the resulting sensor displayed a good response to H₂O₂ with a linear range of 1 to 500 μM, and a detection limit of 1 μM at a signal-to-noise ratio of 3. A linear correlation was established between absorbance intensity and concentration of glucose from 10 to 2000 μM, with a detection limit of 10 μM. The current work presents a simple, cheap, more convenient, sensitive, and easy handling colorimetric assay. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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9 pages, 1338 KiB

Open AccessArticle

Rapid Detection of Glycogen Synthase Kinase-3 Activity in Mouse Sperm Using Fluorescent Gel Shift Electrophoresis

by Hoseok Choi^1,2,†, Bomi Choi^1,2,†, Ju Tae Seo³, Kyung Jin Lee⁴, Myung Chan Gye^1,2,* and Young-Pil Kim^1,2,5,6,*

¹ Department of Life Science, Hanyang University, Seoul 04763, Korea

² Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea

³ Department of Urology, College of Medicine, Dankook University, Cheil General Hospital, Seoul 04619, Korea

⁴ Department of Convergence Medicine, Asan Institute for Life Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea

⁵ Institute of Nano Science and Technology, Hanyang University, Seoul 04763, Korea

⁶ Research Institute for Convergence of Basic Sciences, Hanyang University, Seoul 04763, Korea

^† These authors contributed equally to this work.

Sensors 2016, 16(4), 551; https://doi.org/10.3390/s16040551 - 16 Apr 2016

Cited by 4 | Viewed by 6761

Abstract

Assaying the glycogen synthase kinase-3 (GSK3) activity in sperm is of great importance because it is closely implicated in sperm motility and male infertility. While a number of studies on GSK3 activity have relied on labor-intensive immunoblotting to identify phosphorylated GSK3, here we [...] Read more.

Assaying the glycogen synthase kinase-3 (GSK3) activity in sperm is of great importance because it is closely implicated in sperm motility and male infertility. While a number of studies on GSK3 activity have relied on labor-intensive immunoblotting to identify phosphorylated GSK3, here we report the simple and rapid detection of GSK3 activity in mouse sperm using conventional agarose gel electrophoresis and a fluorescent peptide substrate. When a dye-tethered and prephosphorylated (primed) peptide substrate for GSK3 was employed, a distinct mobility shift in the fluorescent bands on the agarose was observed by GSK3-induced phosphorylation of the primed peptides. The GSK3 activity in mouse testes and sperm were quantifiable by gel shift assay with low sample consumption and were significantly correlated with the expression levels of GSK3 and p-GSK3. We suggest that our assay can be used for reliable and rapid detection of GSK3 activity in cells and tissue extracts. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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7 pages, 1550 KiB

Open AccessArticle

Reverse-Bumpy-Ball-Type-Nanoreactor-Loaded Nylon Membranes as Peroxidase-Mimic Membrane Reactors for a Colorimetric Assay for H₂O₂

by Ying Tong

, Xiangyu Jiao, Hankun Yang, Yongqiang Wen, Lei Su^*

and Xueji Zhang^*

Research Center for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China

Sensors 2016, 16(4), 465; https://doi.org/10.3390/s16040465 - 1 Apr 2016

Cited by 5 | Viewed by 6245

Abstract

Herein we report for the first time fabrication of reverse bumpy ball (RBB)-type-nanoreactor-based flexible peroxidase-mimic membrane reactors (MRs). The RBB-type nanoreactors with gold nanoparticles embedded in the inner walls of carbon shells were loaded on nylon membranes through a facile filtration approach. The [...] Read more.

Herein we report for the first time fabrication of reverse bumpy ball (RBB)-type-nanoreactor-based flexible peroxidase-mimic membrane reactors (MRs). The RBB-type nanoreactors with gold nanoparticles embedded in the inner walls of carbon shells were loaded on nylon membranes through a facile filtration approach. The as-prepared flexible catalytic membrane was studied as a peroxidase-mimic MR. It was found that the obtained peroxidase-mimic MR could exhibit several advantages over natural enzymes, such as facile and good recyclability, long-term stability and easy storage. Moreover, the RBB NS-modified nylon MRs as a peroxidase mimic provide a useful colorimetric assay for H₂O₂. Full article

(This article belongs to the Special Issue Colorimetric and Fluorescent Sensor)

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