Electrochemical Characteristics of Aptasensor Based on MEMS Thin-Film Gold Electrode

A new fabrication methods of thin-film gold electrode is reported. Electrochemical characteristics of self-assembly aptasensor based on MEMS thin-film gold electrode has been studied by lots of experiments, characteristics include immobilizing time, AC impedance, CV curves. Experiments indicate immobilizing time of DNA-SH on gold electrode is more than 15 hours. CV curves and AC impedance of MEMS thin-film gold electrode show the same conclusion that 20μm/L DNA is optimum concentration when DNA is immobilized on gold electrode. Those results present a potential universal method for other aptasensors.

Download Full-text

Construction of Nano Coenzyme and Enzyme Multilayer Film on Gold Electrode by Self-Assembly Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.788.69 ◽

2013 ◽

Vol 788 ◽

pp. 69-72

Author(s):

Kun Yun He ◽

Xing Sheng Wang ◽

Hai Tao Zheng ◽

Shin Ichiro Suye

Keyword(s):

Thin Film ◽

Self Assembly ◽

Nicotinamide Adenine Dinucleotide ◽

Gold Electrode ◽

Multilayer Film ◽

Current Response ◽

Layer By Layer ◽

Assembly Method ◽

Glucose 6 Phosphate Dehydrogenase ◽

Atom Force Microscope

A ferrocene labeled high molecular weight coenzyme derivative (PEI-Fc-NAD) was prepared by attaching both ferrocene (Fc) and coenzyme (nicotinamide adenine dinucleotide, NAD+) to the backbone of poly (ethylenimine) (PEI). A NAD-dependent glucose-6-phosphate dehydrogenase (G6PDH) was used with PEI-Fc-NAD to fabricate a multilayer film on gold electrode by layer-by-layer self-assembly method. The G6PDH/PEI-Fc-NAD multilayer film was characterized by atom force microscope and electrochemical experiment, which proved that a nanostructure thin film was immobilized by the LBL technique. The modified electrode showed the current response to glucose-6-phosphate in the absence of free coenzyme, and kept about 85% response after storage in buffer for 2 month.

Download Full-text

Electrochemical Properties of Lipid Membranes Self-Assembled from Bicelles

Membranes ◽

10.3390/membranes11010011 ◽

2020 ◽

Vol 11 (1) ◽

pp. 11

Author(s):

Damian Dziubak ◽

Kamil Strzelak ◽

Slawomir Sek

Keyword(s):

Electrochemical Properties ◽

Self Assembly ◽

Lipid Membranes ◽

Lipid Membrane ◽

Membrane Resistance ◽

Electrochemical Characteristics ◽

Freeze Thaw ◽

Lipid Films ◽

Supported Lipid Membranes

Supported lipid membranes are widely used platforms which serve as simplified models of cell membranes. Among numerous methods used for preparation of planar lipid films, self-assembly of bicelles appears to be promising strategy. Therefore, in this paper we have examined the mechanism of formation and the electrochemical properties of lipid films deposited onto thioglucose-modified gold electrodes from bicellar mixtures. It was found that adsorption of the bicelles occurs by replacement of interfacial water and it leads to formation of a double bilayer structure on the electrode surface. The resulting lipid assembly contains numerous defects and pinholes which affect the permeability of the membrane for ions and water. Significant improvement in morphology and electrochemical characteristics is achieved upon freeze–thaw treatment of the deposited membrane. The lipid assembly is rearranged to single bilayer configuration with locally occurring patches of the second bilayer, and the number of pinholes is substantially decreased. Electrochemical characterization of the lipid membrane after freeze–thaw treatment demonstrated that its permeability for ions and water is significantly reduced, which was manifested by the relatively high value of the membrane resistance.

Download Full-text

Label-Free Electrochemical Test of Protease Interaction with a Peptide Substrate Modified Gold Electrode

Chemosensors ◽

10.3390/chemosensors9080199 ◽

2021 ◽

Vol 9 (8) ◽

pp. 199

Author(s):

Anna Wcisło ◽

Izabela Małuch ◽

Paweł Niedziałkowski ◽

Tadeusz Ossowski ◽

Adam Prahl

Keyword(s):

Gold Electrode ◽

High Selectivity ◽

Electrode Materials ◽

Electrochemical Biosensors ◽

Electrochemical Characteristics ◽

Label Free ◽

Peptide Substrate ◽

Electrochemical Test ◽

Experimental Conditions ◽

Spectrofluorimetric Method

Efficient deposition of biomolecules on the surface, maintaining their full activity and stability, is a most significant factor in biosensor construction. For this reason, more and more research is focused on the development of electrochemical biosensors that have the ability to electrically detect adsorbed molecules on electrode surface with high selectivity and sensitivity. The presented research aims to develop an efficient methodology that allows quantification of processes related to the evaluation of enzyme activity (proprotein convertase) using electrochemical methods. In this study we used impedance spectroscopy to investigate the immobilization of peptide substrate (Arg-Val-Arg-Arg) modified with 11-mercaptoundecanoic acid on the surface of gold electrode. Both the synthesis of the peptide substrate as well as the full electrochemical characteristics of the obtained electrode materials have been described. Experimental conditions, including concentration of peptide substrate immobilization, modification time, linker, and the presence of additional blocking groups have been optimized. The main advantages of the described method is that it makes it possible to observe the peptide substrate–enzyme interaction without the need to use fluorescent labels. This also allows observation of this interaction at a very low concentration. Both of these factors make this new technique competitive with the standard spectrofluorimetric method.

Download Full-text

Precise Synthesis and Thin Film Self-Assembly of PLLA-b-PS Bottlebrush Block Copolymers

Molecules ◽

10.3390/molecules26051412 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1412

Author(s):

Eunkyung Ji ◽

Cian Cummins ◽

Guillaume Fleury

Keyword(s):

Thin Film ◽

Block Copolymers ◽

Self Assembly ◽

Ring Opening ◽

Periodic Structures ◽

One Pot ◽

Ordered Structures ◽

Carbonyl Chloride ◽

Thin Film Patterning ◽

Nanoporous Templates

The ability of bottlebrush block copolymers (BBCPs) to self-assemble into ordered large periodic structures could greatly expand the scope of photonic and membrane technologies. In this paper, we describe a two-step synthesis of poly(l-lactide)-b-polystyrene (PLLA-b-PS) BBCPs and their rapid thin-film self-assembly. PLLA chains were grown from exo-5-norbornene-2-methanol via ring-opening polymerization (ROP) of l-lactide to produce norbornene-terminated PLLA. Norbonene-terminated PS was prepared using anionic polymerization followed by a termination reaction with exo-5-norbornene-2-carbonyl chloride. PLLA-b-PS BBCPs were prepared from these two norbornenyl macromonomers by a one-pot sequential ring opening metathesis polymerization (ROMP). PLLA-b-PS BBCPs thin-films exhibited cylindrical and lamellar morphologies depending on the relative block volume fractions, with domain sizes of 46–58 nm and periodicities of 70–102 nm. Additionally, nanoporous templates were produced by the selective etching of PLLA blocks from ordered structures. The findings described in this work provide further insight into the controlled synthesis of BBCPs leading to various possible morphologies for applications requiring large periodicities. Moreover, the rapid thin film patterning strategy demonstrated (>5 min) highlights the advantages of using PLLA-b-PS BBCP materials beyond their linear BCP analogues in terms of both dimensions achievable and reduced processing time.

Download Full-text

Fully transparent and flexible humidity sensors fabricated by layer-by-layer self-assembly of thin film of poly(2-acrylamido-2-methylpropane sulfonate) and its salt complex

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2010.09.074 ◽

2011 ◽

Vol 153 (1) ◽

pp. 29-36 ◽

Cited By ~ 44

Author(s):

Pi-Guey Su ◽

Wei-Chen Li ◽

Jiun-Yi Tseng ◽

Chao-Jen Ho

Keyword(s):

Thin Film ◽

Self Assembly ◽

Layer By Layer ◽

Humidity Sensors ◽

Salt Complex

Download Full-text

Precrystalline P3HT nanowires: growth-controllable solution processing and effective molecular packing transfer to thin-film

CrystEngComm ◽

10.1039/d1ce01536b ◽

2022 ◽

Author(s):

Seon-Mi Jin ◽

Jun Ho Hwang ◽

Jung Ah Lim ◽

Eunji Lee

Keyword(s):

Thin Film ◽

Conjugated Polymers ◽

Self Assembly ◽

Optoelectronic Devices ◽

Molecular Packing ◽

Solution Processing ◽

Roll To Roll ◽

Nanowires Growth ◽

Fundamental Research ◽

Significant Attention

Solution-processable precrystalline nanowires (NWs) of conjugated polymers (CPs) have garnered significant attention in fundamental research based on crystallization-driven self-assembly and in the roll-to-roll fabrication of optoelectronic devices such as organic...

Download Full-text