scholarly journals Different Electrochemical Sensor Designs Based on Diazonium Salts and Gold Nanoparticles for Pico Molar Detection of Metals

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3903 ◽  
Author(s):  
Zouhair Ait-Touchente ◽  
Sana Falah ◽  
Erika Scavetta ◽  
Mohamed M. Chehimi ◽  
Rachid Touzani ◽  
...  
Keyword(s):  
Thin Films ◽  
Gold Nanoparticles ◽  
Indium Tin Oxide ◽  
Electrode Surface ◽  
Diazonium Salt ◽  
High Sensitivity ◽  
Diazonium Salts ◽  
Hybrid Nanomaterial ◽  
Ito Electrode ◽  
Hybrid Thin Films

We report a comparison of sensors’ performance of different hybrid nanomaterial architectures modifying an indium tin oxide (ITO) electrode surface. Diazonium salts and gold nanoparticles (AuNPs) were used as building units to design hybrid thin films of successive layers on the ITO electrode surface. Different architectures of hybrid thin films were prepared and characterized with different techniques, such as TEM, FEG-SEM, XPS, and EIS. The prepared electrodes were used to fabricate sensors for heavy metal detection and their performances were investigated using the square wave voltammetry (SWV) method. The comparison of the obtained results shows that the deposition of AuNPs on the ITO surface, and their subsequent functionalization by diazonium salt, is the best performing architecture achieving a high sensitivity in terms of the lower detection limit of pico molar.

scholarly journals Electrochemical Impedance Characterization of Cell Growth on Reduced Graphene Oxide–Gold Nanoparticles Electrodeposited on Indium Tin Oxide Electrodes

2019 ◽  
Vol 9 (2) ◽  
pp. 326 ◽  
Author(s):  
Somasekhar Chinnadayyala ◽  
Jinsoo Park ◽  
Yonghyun Choi ◽  
Jae-Hee Han ◽  
Ajay Yagati ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Cell Growth ◽  
Reduced Graphene Oxide ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Electrochemical Impedance ◽  
Hek293 Cells ◽  
Ito Electrode ◽  
Reduced Graphene

The improved binding ability of graphene–nanoparticle composites to proteins or molecules can be utilized to develop new cell-based assays. In this study, we fabricated reduced graphene oxide–gold nanoparticles (rGO-AuNP) electrodeposited onto a transparent indium tin oxide (ITO) electrode and investigated the feasibility of the electrochemical impedance monitoring of cell growth. The electrodeposition of rGO–AuNP on the ITO was optically and electrochemically characterized in comparison to bare, rGO-, and AuNP-deposited electrodes. The cell growth on the rGO–AuNP/ITO electrode was analyzed via electrochemical impedance measurement together with the microscopic observation of HEK293 cells transfected with a green fluorescent protein expression vector. The results showed that rGO–AuNP was biocompatible and induced an increase in cell adherence to the electrode when compared to the bare, AuNP-, or rGO-deposited ITO electrode. At 54 h cultivation, the average and standard deviation of the saturated normalized impedance magnitude of the rGO–AuNP/ITO electrode was 3.44 ± 0.16, while the value of the bare, AuNP-, and rGO-deposited ITO electrode was 2.48 ± 0.15, 2.61 ± 0.18, and 3.01 ± 0.25, respectively. The higher saturated value of the cell impedance indicates that the impedimetric cell-based assay has a broader measurement range. Thus, the rGO–AuNP/ITO electrode can be utilized for label-free and real-time impedimetric cell-based assays with wider dynamic range.

scholarly journals Diazonium Salts: Versatile Molecular Glues for Sticking Conductive Polymers to Flexible Electrodes

Surfaces ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 43-58 ◽  
Author(s):  
Momath Lo ◽  
Rémi Pires ◽  
Karim Diaw ◽  
Diariatou Gningue-Sall ◽  
Mehmet A. Oturan ◽  
...  
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Electrochemical Impedance ◽  
Conductive Polymers ◽  
Protective Coatings ◽  
Thin Layers ◽  
Diazonium Salts ◽  
Power Sources ◽  
Hydrophobic Character ◽  
Soft Electronics

Adhesion of polymers to surfaces is of the upmost importance in timely applications such as protective coatings, biomaterials, sensors, new power sources and soft electronics. In this context, this work examines the role of molecular interactions in the adhesion of polypyrrole thin films to flexible Indium Tin Oxide (ITO) electrodes grafted with aryl layers from various diazonium salts, namely 4-carboxybenzenediazonium (ITO-CO2H), 4-sulfonicbenzenediazonium (ITO-SO3H), 4-N,N-dimethylbenzenediazonium (ITO-N(CH3)2), 4-aminobenzenediazonium (ITO-NH2), 4-cyanobenzenediazonium (ITO-CN) and 4-N-phenylbenzenediazonium (ITO-NHPh). It was demonstrated that PPy thin layers were adherent to all aryl-modified surfaces, whereas adhesive failure was noted for bare ITO following simple solvent washing or sonication. Adhesion of polypyrrole was investigated in terms of hydrophilic/hydrophobic character of the underlying aryl layer as probed by contact angle measurements. It was found that sulfonic acid-doped polypyrrole (PPy-BSA) thin films were preferably deposited on the most hydrophobic surfaces. More importantly, the redox properties and electrochemical impedance of PPy were closely related to the hydrophobic character of the aryl layers. This work demonstrates that diazonium compounds are unique molecular glues for conductive polymers and permit to tune their interfacial properties. With robust, diazonium-based architectured interfaces, one can design high performance materials for e.g., sensors, printed soft electronics and flexible thermoelectrics.

scholarly journals Diazonium Salts: Versatile Molecular Glues for Sticking Conductive Polymers to Flexible Electrodes

2018 ◽  
Author(s):  
Momath Lo ◽  
Rémi Pires ◽  
Karim Diaw ◽  
Diariatou Gningue-Sall ◽  
Mehmet A. Oturan ◽  
...  
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Electrochemical Impedance ◽  
Conductive Polymers ◽  
Protective Coatings ◽  
Thin Layers ◽  
Diazonium Salts ◽  
Power Sources ◽  
Hydrophobic Character ◽  
Soft Electronics

Adhesion of polymers to surfaces is of upmost importance in timely applications such as protective coatings, biomaterials, sensors, new power sources and soft electronics. In this context, this work examines the role of molecular interactions in the adhesion of polypyrrole thin films to flexible Indium Tin Oxide (ITO) electrodes grafted with aryl layers from various diazonium salts, namely 4-carboxybenzenediazonium (ITO-CO2H), 4-sulfonicbenzenediazonium (ITO-SO3H), 4-N,N dimethylbenzenediazonium (ITO-N(CH3)2), 4-aminobenzenediazonium (ITO-NH2), 4-cyanobenzenediazonium (ITO-CN) and 4-N-phenylbenzenediazonium (ITO-NHPh). It was demonstrated that PPy thin layers were adherent to these surfaces, whereas adhesion failure was noted on bare ITO, following simple solvent washing or sonication. Adhesion of the polypyrrole was investigated in terms of the hydrophilic/hydrophobic character of the underlying aryl layer as probed by contact angle measurements. It was found that sulfonic acid doped polypyrrole (PPy-BSA) thin films were preferably deposited on the most hydrophobic surfaces. More importantly, the redox properties and electrochemical impedance of PPy were closely related to the hydrophobic character of the aryl layers. This work demonstrates that diazonium compounds are unique molecular glues for conductive polymers, and permit to tune their interfacial properties. With diazonium-based robust, architectured interfaces, one can design high performance materials for e.g.sensors, printed soft electronics and flexible thermoelectrics.

Anode Buffer for Organic Devices Composed of Gold Nanoparticles Prepared by Ark Plasma Deposition

2014 ◽  
Vol 896 ◽  
pp. 451-454
Author(s):  
Dan Wang ◽  
Noriaki Yukitake ◽  
Katsuhiko Fujita
Keyword(s):  
Gold Nanoparticles ◽  
Indium Tin Oxide ◽  
Plasma Deposition ◽  
Bulk Heterojunction ◽  
Hole Injection ◽  
Au Nps ◽  
Plasma Gun ◽  
Ito Electrode ◽  
Buffer Material ◽  
Branched Polystyrene

Gold nanoparticles (Au NPs) with mean size of 1 nm were placed on an indium tin oxide (ITO) electrode by ark plasma gun. The hole injection at ITO/organic semiconductor was significantly enhanced by the NPs. Though the hole current was unstable upon the voltage scan, it can be substantially stabilized by the insertion of hyper-branched polystyrene (HPS) thin layer between ITO and Au NPs. The work function of ITO electrode was also increased by NPs. The ITO/HPS/Au NPs structure was applied to the anode of an organic solar cell (OSC) with a bulk heterojunction active layer. The power conversion efficiency was significantly higher than that of OSC without anode buffer layer and almost comparable to that with a representative buffer material.

Spectro-Electrochemical of Detection Anthracene at Electrodeposited Polyamic Acid Thin Films

2016 ◽  
Vol 44 ◽  
pp. 63-78 ◽  
Author(s):  
Xolani Terrance Ngema ◽  
Meryk Ward ◽  
Siyabulela Hamnca ◽  
Priscilla Gloria Lorraine Baker ◽  
Emmanuel Iheanyichukwu Iwuoha
Keyword(s):  
Thin Films ◽  
Cyclic Voltammetry ◽  
Indium Tin Oxide ◽  
High Sensitivity ◽  
Cost Effective ◽  
Electrochemical Analysis ◽  
Polyamic Acid ◽  
Alternative Material ◽  
Polycyclic Aromatic ◽  
Analytical Response

Polyamic acid (PAA) thin films were prepared by electrodepositing PAA onto indium tin oxide (ITO) electrode and characterized using electrochemical methods (cyclic voltammetry, square wave voltammetry), Ultraviolet Visible spectroscopy and Ultraviolet Visible/Spectro-electrochemistry (UV/vis Spectro-electrochemistry). The electrodeposited PAA thin films were observed to have two redox couples with a formal of 118 mV and 274 mV. The diffusion coefficient (De) determined from cyclic voltammetry was found to be 7.9x10-6 cm2/s and provide a measure of how fast charge is transported through the thin film. PAA showed a broad absorption peak at 214 nm due to the carbonyl chromophores within the polymer and shoulder peak at 293 nm from a quinoid-type chromophore. The calculated band gap of 4.23 eV suggested the polymer was optically transparent between 300 nm to 800 nm. This indicated that the PAA thin films has emerged as a very promising and cost effective alternative material to ITO with good transparent and conductive properties. PAA thin films were further applied for the detection of anthracene. The analytical response of anthracene was studied at the ITO/PAA using spectro-electrochemistry. The characteristic analytical absorbance signal for anthracene was clearly identified at 375 nm when ITO/PAA electrode was polarised at -800 mV (vs Ag/AgCl). The calibration curve for anthracene showed a linear response from 4.95x10-4 to 1.15x10-2 M. The ITO/PAA showed a low detection limit of (0.0068 g/L) and high sensitivity for anthracene, making it a suitable platform for spectro-electrochemical analysis of polycyclic aromatic hydrocarbons.

Photo-induced Optical and Chemical Properties of Polysilane/Inorganic Nano-Hybrids

2004 ◽  
Vol 847 ◽  
Author(s):  
Kimihiro Matsukawa ◽  
Yukihito Matsuura
Keyword(s):  
Thin Films ◽  
Gold Nanoparticles ◽  
Refractive Index ◽  
Sol Gel ◽  
Chemical Properties ◽  
High Refractive Index ◽  
Refractive Index Difference ◽  
Hybrid Thin Films ◽  
Organic Photonics ◽  
And Chemical Properties

ABSTRACTPolysilane/inorganic (silica, titania) nano-hybrids might be attractive materials for organic photonics. Polymethylphenylsilane (PMPS)/silica nano-hybrid thin films were prepared by a sol-gel reaction of PMPS block copolymers with alkoxysilanes. The refractive index of hybrid thin films could be controlled with the composition ratio of PMPS, and the value was changed by UV irradiation accompanying photodecomposition of PMPS. After development of the irradiated hybrid thin films, nano porous (ca. 20nm) silica thin films were generated by removing the decomposed PMPS segments and a high refractive index difference occurred between irradiated and non-irradiated part in the hybrid thin films. Furthermore, under photodecomposition of polysilane copolymers, polysilane functioned as a reducing agent of gold (III) ions to prepare the gold nanoparticles.

Electrochemical Immunosensor for Carcinoembryonic Antigen Detection Based on Mo–Mn3O4/MWCNTs/Chits Nanocomposite Modified ITO Electrode

NANO ◽  
2015 ◽  
Vol 10 (08) ◽  
pp. 1550111 ◽  
Author(s):  
Wen-Ting Li ◽  
Yu Wang ◽  
Fen-Fang Deng ◽  
Li-Li Liu ◽  
Hai-Jun Nan ◽  
...  
Keyword(s):  
Carcinoembryonic Antigen ◽  
Indium Tin Oxide ◽  
Incubation Temperature ◽  
Sol Gel ◽  
High Sensitivity ◽  
Electrochemical Immunosensor ◽  
Ito Electrode ◽  
Potential Applications ◽  
Recognition Systems

A novel electrochemical immunosensor for determination of carcinoembryonic antigen (CEA) in human serum was fabricated by depositing Mo–Mn3O4/MWCNTs/Chits nanocomposite onto an indium-tin oxide (ITO) electrode. Mo-doped Mn3O4 (MMO) was synthesized by sol–gel method and the presence of molybdenum improved its electrochemical properties. The MMO/MWCNTs/Chits nanocomposite could accelerate the electron transfer rate and enlarge the surface area to capture a large number of Carcinoembryonic Antigen (CEA). The factors influencing the performance of the immunosensor were investigated, such as incubation time, incubation temperature and pH. Under optimal conditions, the electrochemical immunosensor could detect CEA in a linear range from 0.1[Formula: see text]ng[Formula: see text][Formula: see text][Formula: see text]mL[Formula: see text] to 125[Formula: see text]ng[Formula: see text][Formula: see text][Formula: see text]mL[Formula: see text] with a detection limit of 4.9[Formula: see text]pg[Formula: see text][Formula: see text][Formula: see text]mL[Formula: see text] ([Formula: see text][Formula: see text]). In addition, it exhibited high sensitivity and acceptable stability on a promising immobilization platform for signal amplification, which could be extended to other labeled recognition systems. This electrochemical immunosensor may provide potential applications for the clinical diagnosis.

Fabrication of Novel CuO Films with Nanoparticles-Aggregated Sphere-Like Clusters on ITO and Their Nonenzymatic Glucose Sensing Applications

NANO ◽  
2017 ◽  
Vol 12 (02) ◽  
pp. 1750015 ◽  
Author(s):  
Fang Sun ◽  
Hongwei Jiang ◽  
Ruihua Zhu ◽  
Dan Wang
Keyword(s):  
Indium Tin Oxide ◽  
Amperometric Detection ◽  
High Sensitivity ◽  
Glucose Sensing ◽  
Chloride Ions ◽  
Long Term Stability ◽  
Sensing Applications ◽  
Ito Electrode ◽  
Ito Glass ◽  
Operating Potential

In this work, novel nanoparticles-aggregated CuO sphere-like clusters were successfully synthesized on indium tin oxide (ITO) glass through a facile two-step procedure consisting of the fabrication of Cu2O films directly grown on ITO surface by electrodeposition, and subsequent calcinations of Cu2O films leading to the formation of CuO films. The morphology and structure of as-synthesized samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the size of nanoparticles constituting sphere-like clusters structure obtained at 200[Formula: see text]C is much smaller than that of obtained at other temperature, which can provide large surface area for catalytic reaction. The CuO/ITO electrode was applied to detect glucose by cyclic voltammetry (CV) and amperometric detection ([Formula: see text]). It was found that the obtained CuO films modified ITO electrode exhibited a much higher electrocatalytic activity for the oxidation of glucose in an alkaline medium through heat treatment of 200[Formula: see text]C. A favorable performance with a high sensitivity of 1841.5544[Formula: see text][Formula: see text]A mM[Formula: see text] cm[Formula: see text] to glucose ranging from 1.0[Formula: see text][Formula: see text][Formula: see text]10[Formula: see text][Formula: see text]M to 5.0[Formula: see text][Formula: see text][Formula: see text]10[Formula: see text][Formula: see text]M, a low operating potential of 0.35 Vversus Ag/AgCl and a fast amperometric response (within 3[Formula: see text]s) were achieved on such CuO/ITO electrode. It also showed outstanding long-term stability and good reproducibility. Notably, poisoning by chloride ions and interference from ascorbic acid, uric acid and acetaminophen were negligible. Therefore, the nanoparticles-aggregated CuO sphere-like clusters would be a promising candidate electrode material for the development of nonenzymatic glucose sensors.

scholarly journals Facile Synthesis of CuO/ITO Film Via the Chronoamperometric Electrodeposition for Nonenzymatic Glucose Sensing

2020 ◽  
Vol 30 (2) ◽  
pp. 161
Author(s):  
Duong Thi Thuy Tran ◽  
Dung Quoc Nguyen ◽  
Chuyen Hong Pham ◽  
Lam Dai Tran ◽  
Dai Tien Nguyen
Keyword(s):  
Electrochemical Properties ◽  
Indium Tin Oxide ◽  
Glucose Sensor ◽  
High Sensitivity ◽  
Glucose Sensing ◽  
Serum Samples ◽  
Glucose Response ◽  
X Ray ◽  
Ito Electrode ◽  
Naoh Solution

We report on the synthesis of copper (II) oxide (CuO)/indium tin oxide (ITO) electrode via the electrochemical deposition method using a CuSO4 solution and then thermal oxidation in air at temperature of 400 oC for 2 h. The crystalline structure and morphology of CuO were characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The electrochemical properties of the CuO/ITO electrode to glucose in the alkaline medium of 0.1 M NaOH solution were investigated by cyclic voltammetry (CV) and Chronnoamperometry. The CuO-N/ITO electrode showed the best electrochemical properties for glucose detection in comparison to the others. Chronnoamperometry of CuO-N/ITO electrode to the glucose response showed excellent stability, the linear range of 1 mM to 3600 mM with high sensitivity of 283.6 mAcm-2mM-1 and 0.61 mM of the detection limit (S/N=3). A good response of the CuO-N/ITO electrode, which was investigated for different human serum samples, indicates a high potential of its towards a glucose sensor for analysis in real examples.

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