scholarly journals Development of an Enzyme-Coated Microcantilever-Based Biosensor for Specific Detection of Short-Chain Alcohols

2021 ◽  
Vol 6 (1) ◽  
pp. 75
Author(s):  
Alexandre Margarido ◽  
Livia Regina Manzine ◽  
Fernando M. Araujo-Moreira ◽  
Renato Vitalino Gonçalves ◽  
Paulo Sergio de Paula Herrmann
Keyword(s):  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Short Chain ◽  
Self Assembled Monolayers ◽  
Specific Detection ◽  
Force Microscopy ◽  
Nonpolar Solvents ◽  
Atomic Force ◽  
Assembled Monolayers ◽  
Enzymatic Detection

This paper describes the development of a biosensor designed for the enzymatic detection of short-chain alcohols. The biorecognition element, alcohol dehydrogenase, was immobilized on self-assembled monolayers deposited on top of silicon nitride microcantilevers. The self-assembly process was performed by surface activation using 3-aminopropyltriethoxysilane, followed by glutaraldehyde and biomolecule binding. X-ray photoelectron spectroscopy and atomic force microscopy were used. The biosensor showed a lower response time and sensibility from 0.03 to 1.2 mL/L. Its selectivity was analyzed through exposure to pure and mixed volatile solvents. Sensor sensibility was higher in the presence of short-chain alcohols and practically null involving other polar or nonpolar solvents.

scholarly journals Surface assembly and nanofabrication of 1,1,1-tris(mercaptomethyl)heptadecane on Au(111) studied with time-lapse atomic force microscopy

2014 ◽  
Vol 5 ◽  
pp. 26-35 ◽  
Author(s):  
Tian Tian ◽  
Burapol Singhana ◽  
Lauren E Englade-Franklin ◽  
Xianglin Zhai ◽  
T Randall Lee ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Time Lapse ◽  
Scanning Probe ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Assembly ◽  
Assembled Monolayers ◽  
Liquid Cell

The solution self-assembly of multidentate organothiols onto Au(111) was studied in situ using scanning probe nanolithography and time-lapse atomic force microscopy (AFM). Self-assembled monolayers (SAMs) prepared from dilute solutions of multidentate thiols were found to assemble slowly, requiring more than six hours to generate films. A clean gold substrate was first imaged in ethanolic media using liquid AFM. Next, a 0.01 mM solution of multidentate thiol was injected into the liquid cell. As time progressed, molecular-level details of the surface changes at different time intervals were captured by successive AFM images. Scanning probe based nanofabrication was accomplished using protocols of nanografting and nanoshaving with n-alkanethiols and a tridentate molecule, 1,1,1-tris(mercaptomethyl)heptadecane (TMMH). Nanografted patterns of TMMH could be inscribed within n-alkanethiol SAMs; however, the molecular packing of the nanopatterns was less homogeneous compared to nanopatterns produced with monothiolates. The multidentate molecules have a more complex assembly pathway than monothiol counterparts, mediated by sequential steps of forming S–Au bonds to the substrate.

scholarly journals Self-assembly of octadecyltrichlorosilane: Surface structures formed using different protocols of particle lithography

2012 ◽  
Vol 3 ◽  
pp. 114-122 ◽  
Author(s):  
ChaMarra K Saner ◽  
Kathie L Lusker ◽  
Zorabel M LeJeune ◽  
Wilson K Serem ◽  
Jayne C Garno
Keyword(s):  
Self Assembly ◽  
Self Assembled Monolayers ◽  
Contact Printing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembly Mechanism ◽  
Assembled Monolayers ◽  
Particle Lithography ◽  
Thickness Measurements

Particle lithography offers generic capabilities for the high-throughput fabrication of nanopatterns from organosilane self-assembled monolayers, which offers the opportunity to study surface-based chemical reactions at the molecular level. Nanopatterns of octadecyltrichlorosilane (OTS) were prepared on surfaces of Si(111) using designed protocols of particle lithography combined with either vapor deposition, immersion, or contact printing. Changing the physical approaches for applying molecules to masked surfaces produced OTS nanostructures with different shapes and heights. Ring nanostructures, nanodots and uncovered pores of OTS were prepared using three protocols, with OTS surface coverage ranging from 10% to 85%. Thickness measurements from AFM cursor profiles were used to evaluate the orientation and density of the OTS nanostructures. Differences in the thickness and morphology of the OTS nanostructures are disclosed based on atomic force microscopy (AFM) images. Images of OTS nanostructures prepared on Si(111) that were generated by the different approaches provide insight into the self-assembly mechanism of OTS, and particularly into the role of water and solvents in hydrolysis and silanation.

Self-assembled monolayers of sulfonate-terminated alkanethiols investigated by frequency modulation atomic force microscopy in liquid

2017 ◽  
Vol 28 (45) ◽  
pp. 455603 ◽  
Author(s):  
Hitoshi Asakawa ◽  
Natsumi Inada ◽  
Kaito Hirata ◽  
Sayaka Matsui ◽  
Takumi Igarashi ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Frequency Modulation ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembled Monolayers ◽  
Self Assembled

scholarly journals Mobility of charge carriers in self-assembled monolayers

2019 ◽  
Vol 10 ◽  
pp. 2449-2458
Author(s):  
Zhihua Fu ◽  
Tatjana Ladnorg ◽  
Hartmut Gliemann ◽  
Alexander Welle ◽  
Asif Bashir ◽  
...  
Keyword(s):  
Charge Transport ◽  
Charge Carrier Mobility ◽  
Charge Carriers ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mobility Of Charge Carriers ◽  
Assembled Monolayers ◽  
Self Assembled

We present a new approach to study charge transport within 2D layers of organic semi-conductors (OSCs) using atomic force microscopy (AFM)-based lithography applied to self-assembled monolayers (SAMs), fabricated from appropriate organothiols. The extent of lateral charge transport was investigated by insulating pre-defined patches within OSC-based SAMs with regions of insulating SAM made from large band gap alkanethiolates. The new method is demonstrated using a phenyl-linked anthracenethiolate (PAT), 4-(anthracene-2-ylethynyl)benzyl thiolate. I–V characteristics of differently shaped PAT-islands were measured using the AFM tip as a top electrode. We were able to determine a relationship between island size and electrical conductivity, and from this dependence, we could obtain information on the lateral charge transport and charge carrier mobility within the thin OSC layers. Our study demonstrates that AFM nanografting of appropriately functionalized OSC molecules provides a suitable method to determine intrinsic mobilities of charge carriers in OSC thin films. In particular, this method is rather insensitive with regard to influence of grain boundaries and other defects, which hamper the application of conventional methods for the determination of mobilities in macroscopic samples.

Mechanical Properties of Oligothiophene Self Assembled Films by Atomic Force Microscopy.

2005 ◽  
Vol 871 ◽  
Author(s):  
Imma Ratera ◽  
Jinyu Chen ◽  
Amanda Murphy ◽  
Frank Ogletree ◽  
Jean M. J. Fréchet ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structure Of Molecules ◽  
Cell Dimensions ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Unit Cell Dimensions

AbstractThe oligothiophene derivative (4-(5″″-tetradecyl-[2,2′;5′,2″;5″,2″′;5″′,2″″] pentathiophen-5-yl)-butyric acid (C14-5TBA) was synthesized and the structural and mechanical properties of self-assembled monolayers on mica have been studied by atomic force microscopy (AFM). The films were prepared by drop casting a dilute THF solution (1mM) of the oligothiphene on mica. Islands containing primarily monolayers with a very small percentage of multilayers were formed. The molecules adsorb through the carboxylic group, and expose the alkyl chain (CH2)13CH3. High resolution AFM scans reveal a well ordered structure of molecules with unit cell dimensions of 0.65 and 0.46 nm. Applying load to the tip, the molecular film was gradually compressed from an initial height of 4.1nm to a final one of 2.6 nm, corresponding to atilt of the alkyl chains. In regions covered with bilayers the molecules in the second layer were oriented opposite to those in the first layer, thus exposing the carboxylic end group to the air. These second layer was easily removed as the tip pressure increased.

Sign in / Sign up

Export Citation Format

Share Document