Nanostructured Films: Langmuir–Blodgett (LB) and Layer-by-Layer (LbL) Techniques

Oliveira, Rafael Furlan de; Barros, Anerise de; Ferreira, Marystela

doi:10.1016/b978-0-323-49782-4.00004-8

Cited by 14 publications

(10 citation statements)

References 76 publications

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“…In other techniques derived from dip coating, such as Langmuir-Blodgett (LB) and Langmuir-Shäfer (LS), there is an even more careful control of uniformity and thickness to achieve the formation of just one molecular layer (also called a monolayer) [115]. Specifically, LB involves the coordinated movement of mobile barriers that compress the molecules spread at the air-water interface, and a device that moves the substrate perpendicularly to the solution.…”

Section: Fabrication Techniquesmentioning

confidence: 99%

Organic Thin-Film Transistors as Gas Sensors: A Review

et al. 2020

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Organic thin-film transistors (OTFTs) are miniaturized devices based upon the electronic responses of organic semiconductors. In comparison to their conventional inorganic counterparts, organic semiconductors are cheaper, can undergo reversible doping processes and may have electronic properties chiefly modulated by molecular engineering approaches. More recently, OTFTs have been designed as gas sensor devices, displaying remarkable performance for the detection of important target analytes, such as ammonia, nitrogen dioxide, hydrogen sulfide and volatile organic compounds (VOCs). The present manuscript provides a comprehensive review on the working principle of OTFTs for gas sensing, with concise descriptions of devices’ architectures and parameter extraction based upon a constant charge carrier mobility model. Then, it moves on with methods of device fabrication and physicochemical descriptions of the main organic semiconductors recently applied to gas sensors (i.e., since 2015 but emphasizing even more recent results). Finally, it describes the achievements of OTFTs in the detection of important gas pollutants alongside an outlook toward the future of this exciting technology.

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Section: Fabrication Techniquesmentioning

confidence: 99%

Organic Thin-Film Transistors as Gas Sensors: A Review

et al. 2020

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“…69,70 Coral Salvo-Comino et al developed a layer-by-layer technique for the analysis of milk using a bi-sensor system because of its low cost and intrinsic simplicity. 71 There are two sensing units present in this system. The first sensor consists of anodic and cathodic parts: anodic part is copper sulfonate phthalocyanine (CuPcS), which acts as an electrocatalyst.…”

Section: Discrimination Of Milk With a Multisensor Systemmentioning

confidence: 99%

Amperometric Biosensors as an Analytical Tool in Food, Dairy and Fermentation Industries

Sivashankar¹,

Kumar²,

Kiran³

et al. 2020

IJPSRR

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Biosensors are analytical devices that sense the presence of a biological component in the vicinity and generate signals that can be easily detected using a physicochemical detector. With the advent of biosensors, conventional methodologies such as the detection of contaminants in pharmaceutical industries and the diagnosis of diseases via biomarkers have been accelerated to a great extent. The review highlights the use of Amperometric biosensors in three important industries namely, the food, fermentation, and dairy industries, and highlights the potential use of these biosensors in various domains of these industries. These industries can employ the use of amperometric biosensors to control and monitor the presence of various metabolites and constituents that may either be of economic importance or toxic to the consumers. The continuous monitoring of these metabolites is of prime importance as they ultimately determine the quality of the end product. The review also gives a comprehensive description of the modifications done in the amperometric biosensors, using specific biomolecules and chemicals, along with their associated analytical features.

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“…The appropriate selection of the immobilization surface is of great importance to develop biosensors with enhanced sensing performance. The layer-by-layer (LbL) technique is a suitable alternative to immobilize enzymes without affecting their activity [2][3][4][5]. In addition, LbL films show a high versatility for designing films with different compositions and functionalities with controlled architecture.…”

Section: Introductionmentioning

confidence: 99%

Biosensors Platform Based on Chitosan/AuNPs/Phthalocyanine Composite Films for the Electrochemical Detection of Catechol. The Role of the Surface Structure

Salvo-Comino

González-Gil

Rodriguez-Valentin

et al. 2020

Sensors

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Biosensor platforms consisting of layer by layer films combining materials with different functionalities have been developed and used to obtain improved catechol biosensors. Tyrosinase (Tyr) or laccase (Lac) were deposited onto LbL films formed by layers of a cationic linker (chitosan, CHI) alternating with layers of anionic electrocatalytic materials (sulfonated copper phthalocyanine, CuPcS or gold nanoparticles, AuNP). Films with different layer structures were successfully formed. Characterization of surface roughness and porosity was carried out using AFM. Electrochemical responses towards catechol showed that the LbL composites efficiently improved the electron transfer path between Tyr or Lac and the electrode surface, producing an increase in the intensity over the response in the absence of the LbL platform. LbL structures with higher roughness and pore size facilitated the diffusion of catechol, resulting in lower LODs. The [(CHI)-(AuNP)-(CHI)-(CuPcS)]2-Tyr showed an LOD of 8.55∙10−4 μM, which was one order of magnitude lower than the 9.55·10−3 µM obtained with [(CHI)-(CuPcS)-(CHI)-(AuNP)]2-Tyr, and two orders of magnitude lower than the obtained with other nanostructured platforms. It can be concluded that the combination of adequate materials with complementary activity and the control of the structure of the platform is an excellent strategy to obtain biosensors with improved performances.

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Nanostructured Films: Langmuir–Blodgett (LB) and Layer-by-Layer (LbL) Techniques

Cited by 14 publications

References 76 publications

Organic Thin-Film Transistors as Gas Sensors: A Review

Organic Thin-Film Transistors as Gas Sensors: A Review

Amperometric Biosensors as an Analytical Tool in Food, Dairy and Fermentation Industries

Biosensors Platform Based on Chitosan/AuNPs/Phthalocyanine Composite Films for the Electrochemical Detection of Catechol. The Role of the Surface Structure

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