scholarly journals Porphyrin-Based Nanostructures for Sensing Applications

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Donato Monti ◽  
Sara Nardis ◽  
Manuela Stefanelli ◽  
Roberto Paolesse ◽  
Corrado Di Natale ◽  
...  
Keyword(s):  
Self Assembly ◽  
Metal Ion ◽  
Chemical Sensor ◽  
Noncovalent Interactions ◽  
Chemical Information ◽  
Sensor Applications ◽  
Material Chemistry ◽  
Sensing Applications ◽  
Porphyrin Derivatives ◽  
Molecular Components

The construction of nanosized supramolecular hosts via self-assembly of molecular components is a fascinating field of research. Such intriguing class of architectures, beside their intrinsic intellectual stimuli, is of importance in many fields of chemistry and technology, such as material chemistry, catalysis, and sensor applications. Within this wide scenario, tailored solid films of porphyrin derivatives are structures of great potential for, among others, chemical sensor applications. The formation ofsupramoleculesrelays on noncovalent interactions (electrostatic, hydrogen bond, , or coordinative interactions) driven by the chemical information stored on the assembling molecules, such as shape and functional groups. This allows, for example, the formation of large well-defined porphyrin aggregates in solution that can be spontaneously transferred onto a solid surface, so achieving a solid system with tailored features. These films have been used, covering the bridge between nanostructures and microsystems, for the construction of solid-state sensors for volatiles and metal ion recognition and detection. Moreover, the variation of peripheral substituents of porphyrins, such as, for example, chiral appended functionalities, can result in the formation of porphyrin aggregates featuring high supramolecular chirality. This would allow the achievement of porphyrin layers characterised by different chiroptical and molecular recognition properties.

Multiple Processing of Metal-Ion Coordination, Anion-Binding, Hydrogen-Bonding- Self-Assembly and p-p Stacking Subprograms in Silver (I) oordination Polymers

2008 ◽  
Vol 59 (3) ◽  
pp. 260-265 ◽  
Author(s):  
Pascal Blondeau ◽  
Yves-Marie Legrand ◽  
Arie Van Der Lee ◽  
Gihane Nasr ◽  
Mihail Barboiu
Keyword(s):  
Hydrogen Bonding ◽  
Coordination Polymers ◽  
Self Assembly ◽  
Metal Ion ◽  
Silver Triflate ◽  
Anion Coordination ◽  
Supramolecular Coordination ◽  
Geometrical Information ◽  
Molecular Components ◽  
Multiple Processing

New crystalline coordination-polymers are obtained under conditions in which distinct metal ion coordination, hydrogen-bonding and p-p stacking subprograms are involved in independent binding events of ureidopyridyl ligands 1 and 2 by silver hexafluorophosphate or silver triflate. The geometrical information contained in the structure of the ligands 1 and 2 is fully exploited by the silver ion coordination and urea-self assembly or H-bond anion coordination templating features in an independent way. The resulted linear or angular sequences may serve to use the information stored in molecular components that could be read out by synergistic and sequential non-covalent subprograms. It results in linear or tubular supramolecular coordination polymers constructed in a bottom-up strategy.

Self Assembly in Biologically Synthesized Electrospun Electroactive Polymers

2005 ◽  
Vol 889 ◽  
Author(s):  
A. Bishop ◽  
P. Gouma
Keyword(s):  
Enzyme Immobilization ◽  
Self Assembly ◽  
Charge Separation ◽  
Chemical Sensor ◽  
Electroactive Polymers ◽  
Processing Parameters ◽  
The Self ◽  
Assembly Process ◽  
Composite Matrix ◽  
Sensor Applications

ABSTRACTThe processing parameters of polyaniline (PANI) dictate the desired morphology and overall structural stability of the deposited polymer for biological and chemical sensor applications. Electrospun composites of leucoemeraldine based PANI (LEB-PANI) has exhibited effective separation of aggregates inherent in LEB-PANI powder as a result of charge separation induced on the composite matrix during electrospinning. However it appears the encapsulation of biological (enzyme-Urease E.C.3.5.1.5) in the electrospun matrix intensifies the self assembly process. An investigation of the changes in morphology as an effect of electrospinning and enzyme immobilization is discussed.

Atomic Force Microscopy (AFM) Studies of Cured Self-Assembled Films for Chemical Sensor Applications

2005 ◽  
Vol 11 (S03) ◽  
pp. 114-117
Author(s):  
E. S. Medeiros ◽  
R. Bernardes Filho ◽  
R. A. Martinez ◽  
R. Gregorio Filho ◽  
L. H. C. Mattoso
Keyword(s):  
Self Assembly ◽  
Deposition Time ◽  
Chemical Sensor ◽  
Film Formation ◽  
Force Microscopy ◽  
Sensor Applications ◽  
Atomic Force ◽  
Efficient Control ◽  
Sensitivity And Selectivity ◽  
Ultrathin Polymer Films

The use of ultrathin polymer films as sensoactive layers in chemical sensors has received great interest in recent years due to many advantages such as the wide choice of polymeric system (polymer types and/or combination, dopants in conducting polymers, etc), and the possibility of tailoring the properties of these films in terms of sensitivity and selectivity by an efficient control of the film formation process [1]. Among the techniques used for ultrathin films formation, self-assembly (SA) offers several advantages since the substrate can take any form and size, deposition time is independent of the substrate area, there are no requirements for additional equipments and/or clean rooms, and a large quantity of materials can be assembled into thin films [2-8].

scholarly journals Voltammetric Tracing of Al(III) Using Supramolecular Metal-Polyphenolic Nanofilms Obtained via Electrochemically Assisted Self-Assembly

2020 ◽  
Vol 74 (4) ◽  
pp. 289-292 ◽  
Author(s):  
A. Krywko-Cendrowska
Keyword(s):  
Metal Ions ◽  
Self Assembly ◽  
Metal Ion ◽  
Toxic Metal ◽  
Polyphenolic Compounds ◽  
Colloidal Synthesis ◽  
Naturally Occurring ◽  
Electrical Stimuli ◽  
Molecular Components ◽  
Complexes With Metal Ions

Supramolecular metal-polyphenolic thin sensor films represent a unique class of composite materials. Their properties and sensitivity can be easily modified via controlled self-assembly of their molecular components. Among the different assembly methods, electrochemically triggered processes are extremely powerful because they allow spatial confinement of the film buildup via an electrical stimuli-controlled process. In this article, an approach to employ the electrochemically assisted self-assembly of a multicomponent supramolecular film based on a naturally occurring polyphenol, tannic acid (TA), is featured. Here, the capacity of polyphenolic compounds to form complexes with metal ions, as well as to act both as reducing agents and stabilizers in colloidal synthesis of metal nanoparticles (NPs) is utilized. The electrochemically triggered self-assembly can be coupled with the ion – printing method, in which the targeted metal ion, in this case Al(III), is incorporated into the film during the synthesis and chemically removed afterwards. This procedure results in a template-like structure of the film with openings ready to bind the same metal ion from the probed solution, thus significantly improving the selectivity of the sensor formed and enhancing its applicability for sensing of toxic metal ions in complex aqueous solutions, such as physiological fluids.

scholarly journals Rapid Growth of TiO2 Nanoflowers via Low-Temperature Solution Process: Photovoltaic and Sensing Applications

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 566 ◽  
Author(s):  
M. Akhtar ◽  
Ahmad Umar ◽  
Swati Sood ◽  
InSung Jung ◽  
H. Hegazy ◽  
...  
Keyword(s):  
Low Temperature ◽  
Anatase Phase ◽  
Three Dimensional ◽  
Solution Process ◽  
Dye Sensitized Solar Cell ◽  
Sensor Applications ◽  
Dye Sensitized ◽  
Sensing Applications ◽  
Density Growth ◽  
Temperature Solution

This paper reports the rapid synthesis, characterization, and photovoltaic and sensing applications of TiO2 nanoflowers prepared by a facile low-temperature solution process. The morphological characterizations clearly reveal the high-density growth of a three-dimensional flower-shaped structure composed of small petal-like rods. The detailed properties confirmed that the synthesized nanoflowers exhibited high crystallinity with anatase phase and possessed an energy bandgap of 3.2 eV. The synthesized TiO2 nanoflowers were utilized as photo-anode and electron-mediating materials to fabricate dye-sensitized solar cell (DSSC) and liquid nitroaniline sensor applications. The fabricated DSSC demonstrated a moderate conversion efficiency of ~3.64% with a maximum incident photon to current efficiency (IPCE) of ~41% at 540 nm. The fabricated liquid nitroaniline sensor demonstrated a good sensitivity of ~268.9 μA mM−1 cm−2 with a low detection limit of 1.05 mM in a short response time of 10 s.

Controllable Synthesis of Cobalt Porphyrin Nanocrystals through Micelle Confinement Self-Assembly

MRS Advances ◽  
2020 ◽  
Vol 5 (42) ◽  
pp. 2147-2155
Author(s):  
Sudi Chen ◽  
Xitong Ren ◽  
Shufang Tian ◽  
Jiajie Sun ◽  
Feng Bai
Keyword(s):  
Self Assembly ◽  
Water Oxidation ◽  
Separation Efficiency ◽  
Noncovalent Interactions ◽  
Building Blocks ◽  
The Self ◽  
Hexagonal Prism ◽  
Assembly Process ◽  
Surfactant Micelles ◽  
Cobalt Porphyrin

AbstractThe self-assembly of optically active building blocks into functional nanocrystals as high-activity photocatalysts is a key in the field of photocatalysis. Cobalt porphyrin with abundant catalytic properties is extensively studied in photocatalytic water oxidation and CO2 reduction. Here, we present the fabrication of cobalt porphyrin nanocrystals through a surfactant-assisted interfacial self-assembly process using Co-tetra(4-pyridyl) porphyrin as building block. The self-assembly process relies on the combined noncovalent interactions such as π-π stacking and axial Co-N coordination between individual porphyrin molecules within surfactant micelles. Tuning different reaction conditions (temperature, the ratio of co-solvent DMF) and types of surfactant, various nanocrystals with well-defined 1D to 3D morphologies such as nanowires, nanorods and nano hexagonal prism were obtained. Due to the ordered accumulation of molecules, the nanocrystals exhibit the properties of the enhanced capability of visible light capture and can conduce to improve the transport and separation efficiency of the photogenerated carriers, which is important for photocatalysis. Further studies of photocatalytic CO2 reduction are being performed to address the relationship between the size and shape of the nanocrystals with the photocatalytic activity.

Rapid Silicon-to-Steel Bonding via Inductive Heating

2006 ◽  
Author(s):  
Brian D. Sosnowchik ◽  
Liwei Lin ◽  
Albert P. Pisano
Keyword(s):  
Bonding Temperature ◽  
Surface Preparation ◽  
Fatigue Tests ◽  
Bonding Process ◽  
Inductive Heating ◽  
Sensor Applications ◽  
Mems Sensor ◽  
Sensing Applications ◽  
Minimal Damage ◽  
Point Bend

In this work, we present a rapid, low temperature process for the bonding of silicon to steel through the use of inductive heating for MEMS sensor applications. The bonding process takes as short as three seconds with a maximum bonding temperature as low as 230°C at the steel surface. The bonding strength is strong, and causes minimal damage to steel. The process has also been shown to work using leaded and leadfree bonding solder with minimal surface preparation to the steel. Four characterization experiments – tensile and compressive 4-point bend, axial extension, and fatigue tests – have been performed to validate the bonding process and materials. As such, this work illustrates the promise of applying inductive heating for the rapid silicon bonding to steel components for MEMS sensing applications.

Functionalized polysiloxane thin films deposited by matrix-assisted pulsed laser evaporation for advanced chemical sensor applications

2006 ◽  
Vol 252 (13) ◽  
pp. 4871-4876 ◽  
Author(s):  
E.J. Houser ◽  
D.B. Chrisey ◽  
M. Bercu ◽  
N.D. Scarisoreanu ◽  
A. Purice ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Sensor ◽  
Pulsed Laser ◽  
Laser Evaporation ◽  
Sensor Applications
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