Search

Lithium–sulfur (Li–S) batteries are expected to be one of the next generations of high-energy-density battery systems due to their high theoretical energy density of 2600 Wh kg−1. Embracing the trends toward flexibility, lightweight design, and cost-effectiveness, paper-based electrodes offer a promising alternative to traditional coated cathodes in Li–S batteries. Within paper-based electrodes, conductive fibers such as carbon nanotubes (CNTs) play a crucial role. They help to form a three-dimensional network within the paper matrix to ensure structural integrity over extended cycling while mitigating the shuttle effect by confining sulfur within the cathode. Herein, we explore how variously functionalized CNTs, serving as conductive fibers, impact the physical and electrochemical characteristics of paper-based sulfur cathodes in Li–S batteries. Specifically, graphitized hydroxylated carbon nanotubes (G-CNTs) exhibit remarkable capacity at low currents owing to their excellent conductivity and interaction with lithium polysulfide (LiPS), achieving the highest initial specific capacity of 1033 mAh g−1 at 0.25 C (1.1 mA cm−2). Aminated multi-walled carbon nanotubes (NH2-CNTs) demonstrate an enhanced affinity for LiPS due to the -NH2 groups. However, the uneven distribution of these fibers may induce electrode surface passivation during charge–discharge cycles. Notably, hydroxylated multi-walled carbon nanotubes (OH-CNTs) can establish a uniform and stable 3D network with plant fibers, showcasing superior mechanical properties and helping to mitigate Li2S agglomeration while preserving the electrode porosity. The paper-based electrode integrated with OH-CNTs even retains a specific capacity of approximately 800 mAh g−1 at about 1.25 C (5 mA cm−2), demonstrating good sulfur utilization and rate capacity compared to other CNT variants. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are expected to be one of the next generations of high-energy-density battery systems due to their high theoretical energy density of 2600 Wh kg−1. Embracing the trends toward flexibility, lightweight design, and cost-effectiveness, paper-based electrodes offer a promising alternative to traditional coated cathodes in Li–S batteries. Within paper-based electrodes, conductive fibers such as carbon nanotubes (CNTs) play a crucial role. They help to form a three-dimensional network within the paper matrix to ensure structural integrity over extended cycling while mitigating the shuttle effect by confining sulfur within the cathode. Herein, we explore how variously functionalized CNTs, serving as conductive fibers, impact the physical and electrochemical characteristics of paper-based sulfur cathodes in Li–S batteries. Specifically, graphitized hydroxylated carbon nanotubes (G-CNTs) exhibit remarkable capacity at low currents owing to their excellent conductivity and interaction with lithium polysulfide (LiPS), achieving the highest initial specific capacity of 1033 mAh g−1 at 0.25 C (1.1 mA cm−2). Aminated multi-walled carbon nanotubes (NH2-CNTs) demonstrate an enhanced affinity for LiPS due to the -NH2 groups. However, the uneven distribution of these fibers may induce electrode surface passivation during charge–discharge cycles. Notably, hydroxylated multi-walled carbon nanotubes (OH-CNTs) can establish a uniform and stable 3D network with plant fibers, showcasing superior mechanical properties and helping to mitigate Li2S agglomeration while preserving the electrode porosity. The paper-based electrode integrated with OH-CNTs even retains a specific capacity of approximately 800 mAh g−1 at about 1.25 C (5 mA cm−2), demonstrating good sulfur utilization and rate capacity compared to other CNT variants.

Miniaturized paper‐based electrochemical sensors were fabricated using kraft paper and CO2 laser, dispensing the need for chemical reagents and controlled atmospheric conditions. This study initially evaluated the paper type and laser processing parameters, enhancing the electrodes′ robustness, electrochemical response, and electrical resistance. The sensors were also treated by applying −1 V for 60 s in 1.0 mol L−1 KCl, which is a simple and rapid procedure. The electrochemical treatment increased the electroactive area and roughness, confirmed by scanning electron microscopy. These aspects helped modulate the sensors′ electrochemical response for nitrite determination, improving selectivity and sensitivity for this compound. The sensors also showed repeatability and batch‐to‐batch reproducibility, with 2.2 and 10 % RSD, respectively. Therefore, this work brings a protocol to fabricating competitive electrochemical sensors through a sustainable strategy, opening possibilities for designing new analytical systems. [ABSTRACT FROM AUTHOR]

Abstract Miniaturized paper‐based electrochemical sensors were fabricated using kraft paper and CO2 laser, dispensing the need for chemical reagents and controlled atmospheric conditions. This study initially evaluated the paper type and laser processing parameters, enhancing the electrodes′ robustness, electrochemical response, and electrical resistance. The sensors were also treated by applying −1 V for 60 s in 1.0 mol L−1 KCl, which is a simple and rapid procedure. The electrochemical treatment increased the electroactive area and roughness, confirmed by scanning electron microscopy. These aspects helped modulate the sensors′ electrochemical response for nitrite determination, improving selectivity and sensitivity for this compound. The sensors also showed repeatability and batch‐to‐batch reproducibility, with 2.2 and 10 % RSD, respectively. Therefore, this work brings a protocol to fabricating competitive electrochemical sensors through a sustainable strategy, opening possibilities for designing new analytical systems.

Paper has been increasingly used in recent years as a substrate in the structure of sensors to determine diverse biological and pharmaceutical molecules and ions. Potentiometric sensors built with paper offer certain improvements since they are cost–effective, portable, biodegradable, eco–friendly, disposable and easy to manufacture. Paper is also an ideal substrate to be used, considering that it is flexible, lightweight, mechanically–resistant, a good medium for immobilization and trapping, and that it can be easily chemically and physically modified for customized applications, it can adsorb and transport liquid via capillary forces, can close the electrical circuit between electrodes when wet, it can be produced in diverse geometrical dimensions and porosities. Due to these characteristics, paper–based potentiometric sensors are more eco–friendly, suitable to be used in resource–limited areas, can be used in remote locations or on–site settings with low–cost analytical instrumentation. To our knowledge, the most recent advancements in the field have not been collectively reviewed, and this is of high importance considering the rapid developments made in paper–based potentiometric sensors lately. In these review, we covered paper–based potentiometric devices developed in the very recent years, detailed their structures, and compared their certain performance parameters including detection limit, linear concentration range, response time and applicability. [ABSTRACT FROM AUTHOR]

Paper has been increasingly used in recent years as a substrate in the structure of sensors to determine diverse biological and pharmaceutical molecules and ions. Potentiometric sensors built with paper offer certain improvements since they are cost–effective, portable, biodegradable, eco–friendly, disposable and easy to manufacture. Paper is also an ideal substrate to be used, considering that it is flexible, lightweight, mechanically–resistant, a good medium for immobilization and trapping, and that it can be easily chemically and physically modified for customized applications, it can adsorb and transport liquid via capillary forces, can close the electrical circuit between electrodes when wet, it can be produced in diverse geometrical dimensions and porosities. Due to these characteristics, paper–based potentiometric sensors are more eco–friendly, suitable to be used in resource–limited areas, can be used in remote locations or on–site settings with low–cost analytical instrumentation. To our knowledge, the most recent advancements in the field have not been collectively reviewed, and this is of high importance considering the rapid developments made in paper–based potentiometric sensors lately. In these review, we covered paper–based potentiometric devices developed in the very recent years, detailed their structures, and compared their certain performance parameters including detection limit, linear concentration range, response time and applicability.

[Display omitted] • Paper-based electrodes coated with polymers, mimick the lignocellulosic biomass. • Lignin penetrates deeply in the paper as shown by SEM and CV analyses. • The presence of lignin forms a barrier, avoiding a redox probe to reach the electrode. • Ligninolytic enzymes degraded this biomimetic substrate and allowed to recover the signal. Lignin is the most important natural source of aromatic compounds. The valorisation of lignin into aromatics requires fractionation steps that can be catalysed by ligninolytic enzymes. However, one of the main limitations of biological lignin fractionation is the low efficiency of biocatalysts; it is therefore crucial to enhance or to identify new ligninolytic enzymes. Currently, the screening of ligninolytic activities on lignin polymers represents a technological bottenleck and hinders the characterization and the discovery of efficient ligninolytic biocatalysts. An efficient and fast method for the measurement of such enzymatic activities is therefore required. In this work, we present a new electrochemical tool based on lignin-coated paper electrodes for the detection and the characterization of ligninolytic activity. The suitability of this method is demonstrated using a catalase-peroxidase isolated from Thermobacillus xylanilyticus. [ABSTRACT FROM AUTHOR]

The need for agile and proper identification of drugs of abuse has encouraged the scientific community to improve and to develop new methodologies. The drug lysergic acid diethylamide (LSD) is still widely used due to its hallucinogenic effects. The use of voltammetric methods to analyze narcotics has increased in recent years, and the possibility of miniaturizing the electrochemical equipment allows these methods to be applied outside the laboratory; for example, in crime scenes. In addition to portability, the search for affordable and sustainable materials for use in electroanalytical research has grown in recent decades. In this context, employing paper substrate, graphite pencil, and silver paint to construct paper‐based electrodes is a great alternative. Here, a paper‐based device comprising three electrodes was drawn on 300 g/m2 watercolor paper with 8B pencils, and its efficiency was compared to the efficiency of a commercially available screen‐printed carbon electrode. Square wave voltammetry was used for LSD analysis in aqueous medium containing 0.05 mol/L LiClO4. The limits of detection and quantification were 0.38 and 1.27 μmol/L, respectively. Both electrodes exhibited a similar voltammetric response, which was also confirmed during analysis of a seized LSD sample, with recovery of less than 10%. The seized samples were previously analyzed by GCMS technique, employing the full scan spectra against the software spectral library. The electrode selectivity was also tested against 3,4‐methylenedioxymethamphetamine (MDMA) and methamphetamine. It was possible to differentiate these compounds from LSD, indicating that the developed paper‐based device has potential application in forensic chemistry analyses. [ABSTRACT FROM AUTHOR]

The need for agile and proper identification of drugs of abuse has encouraged the scientific community to improve and to develop new methodologies. The drug lysergic acid diethylamide (LSD) is still widely used due to its hallucinogenic effects. The use of voltammetric methods to analyze narcotics has increased in recent years, and the possibility of miniaturizing the electrochemical equipment allows these methods to be applied outside the laboratory; for example, in crime scenes. In addition to portability, the search for affordable and sustainable materials for use in electroanalytical research has grown in recent decades. In this context, employing paper substrate, graphite pencil, and silver paint to construct paper‐based electrodes is a great alternative. Here, a paper‐based device comprising three electrodes was drawn on 300 g/m2 watercolor paper with 8B pencils, and its efficiency was compared to the efficiency of a commercially available screen‐printed carbon electrode. Square wave voltammetry was used for LSD analysis in aqueous medium containing 0.05 mol/L LiClO4. The limits of detection and quantification were 0.38 and 1.27 μmol/L, respectively. Both electrodes exhibited a similar voltammetric response, which was also confirmed during analysis of a seized LSD sample, with recovery of less than 10%. The seized samples were previously analyzed by GCMS technique, employing the full scan spectra against the software spectral library. The electrode selectivity was also tested against 3,4‐methylenedioxymethamphetamine (MDMA) and methamphetamine. It was possible to differentiate these compounds from LSD, indicating that the developed paper‐based device has potential application in forensic chemistry analyses. [ABSTRACT FROM AUTHOR]

Using disposable screen-printed electrodes is a convenient way of monitoring environmental pollution, production process control etc. Usually, commercially available screen-printed electrodes are used, but more and more studies are being carried out in the field of printing electrodes on thinner, low-cost and versatile substrates, including paper. In the present research, the comparison of screen-printed electrodes printed on different paper-based materials is presented. Two unique and innovative invasive plant-based papers made from (1) Japanese knotweed, (2) Canadian and Giant goldenrod and (3) commercially available cardboard were used as a printing material for the electrodes. The selected paper substrates were characterized, and screen-printed electrodes were printed. The influence of substrates' properties and pre- or post-treatment of the screen-printed electrodes on the electrochemical behaviour is thoroughly analyzed. The results indicate that the printing substrate (roughness) had the most significant influence on the cyclic voltammetry response. Comparing pre- and post-treatment of screen-printed electrodes, it was shown that grinding influenced the electrochemical activity significantly, while corona discharge does not have as significant influence. Besides, it was shown that the invasive plant-based papers are viable alternatives to commercially available papers and can be used as low-cost and eco-friendly alternatives for disposable screen-printed electrodes. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A simple, low cost, and lightweight 3D origami-battery on paper was developed. • The battery was fabricated using printed wax and active electrocatalytic materials. • The 3D-structure contained two screen printed Zn/Fe 3 O 4 batteries in series that were activated with 6 M KOH electrolyte. Abstract A simple, low cost, and lightweight three-dimensional (3D) primary alkaline Zn/Fe 3 O 4 origami-battery fabricated from Whatman 1 paper was developed. The battery was created using printed wax to define the hydrophobic and hydrophilic barriers and active electrocatalytic materials for fabricating the electrodes. The boat-shaped 3D-battery consisted of two screen-printed Zn/Fe 3 O 4 batteries connected in series that were activated with a small volume of aqueous KOH solution. The metallic electrodes were first characterized outside the folded battery using electrochemical techniques. Subsequently, the electrodes and separator were assembled together in a triangle-shaped battery resembling the main structure of the boat-shaped 3D-device and this triangle-shaped battery was further optimized. The addition of water triggered the activation of the 3D battery delivering a maximum current and power of 7 mA and 3 mW, respectively. The 3D-Zn/Fe 3 O 4 -battery displayed an OCP of 2.2 V and a maximum current and power of 22 mA and 7.5 mW, respectively, in the presence of 6 M KOH electrolyte. These results demonstrate the potential of 3D origami-based structures and Zn/Fe 3 O 4 batteries as an alternative low cost energy source to power portable devices. [ABSTRACT FROM AUTHOR]

This work presents the development and optimization of a very low cost, miniaturized and lightweight aluminum/silver oxide (Al/AgO) primary battery. The system is implemented on painted paper supported electrodes and it is activated using a small amount of water. The anode contains an improved composite based on aluminum powder. The cathode is made using an electrical conductive silver epoxy ink. The device displays a paper-based core comprising the electrodes and the paper matrix separator, modified with a highly concentrated dry potassium hydroxide salt, inside a flexible laminated plastic structure that provides sturdiness to the system making it safe and portable for the user. The battery turns on by applying 80 μl of water and as a result the system produces a maximum capacity of 0.5 mAh when 1.6 mA cm −2 are applied. The generated electrical power of two batteries in series is then used to power a LED during approximately one hour. Although there is room for improvement, these results allow envisaging the battery as a real commercial portable power source and allow planning potential uses of this energy to power microelectronics demanding low power consumption, such as sensors or wearable electronics. [ABSTRACT FROM AUTHOR]

Paper has been used for a long time in the production of low-cost point-of-care (POC) detection devices, most of which rely on the detection of colored bands by the user. However, test strips rarely provide the quantitative detection of biomarkers in clinical samples. In contrast, electrochemical detection enables quantitative detection in paper-based immunoassays. Here, we demonstrate the production of a simple and economical lateral-flow electrode device using only screen printing. Contrary to previous work, this device is used to simplify the washing and detection of a short and sensitive immunomagnetic assay for myeloperoxidase (MPO) detection. As we show, after incubation of the sample with magnetic beads (MBs) and detection antibody (Ab) for only 5 min, the whole reaction mixture can be directly pipetted onto the strip. Washing and detection can then be performed, as the MBs are retained with the aid of a magnet, and minimal user intervention is needed. The obtained results reveal that MPO can be detected in 1 : 100 diluted serum with limits of detection and quantification of 0.18 and 0.62 ng mL−1, respectively, in less than 15 min. [ABSTRACT FROM AUTHOR]

Keywords: electrochemical treatment; laser-pyrolyzed; paper-based devices; paper-based electrodes; nitrite EN electrochemical treatment laser-pyrolyzed paper-based devices paper-based electrodes nitrite 1 1 1 01/06/23 20230102 NES 230102 B The Cover Feature b illustrates eco-friendly laser-pyrolyzed paper sensors used for nitrite determination in environmental and biological samples. Cover Feature: Modulating the Electrochemical Response of Eco-Friendly Laser-Pyrolyzed Paper Sensors Applied to Nitrite Determination (ChemElectroChem 1/2023) Electrochemical treatment, laser-pyrolyzed, paper-based devices, paper-based electrodes, nitrite. [Extracted from the article]

The fabrication, characterization, and applications of paper‐based screen‐printed carbon electrodes (SPCE) are discussed. In particular, microscopy images of the working electrode surface show a reproducible 3D pattern that enhances the performance of the device compared to that of a polyester‐based SPCE. Gold nanoparticles and CdSe@ZnS quantum dots are detected using different electrochemical techniques. [ABSTRACT FROM AUTHOR]

In real-life situations, where samples such as wet soil, body fluids or foodstuff, contain high content of solids/impurities with a limited amount of liquid, sample collection within an adsorptive substrate prior ion determination emerges as a necessary step. For this reason, paper-based technology has been widely studied in development of potentiometric sensors and their application in determination of ions in various samples. Paper is easily available, inexpensive, capable of wicking fluids, disposable and biodegradable, thus provides clear benefits to be integrated with potentiometric ion sensors. In turn, potentiometric ion sensors are characterized by relatively cheap and compact design and, most importantly, by the ability to perform quick and easy ion determination. In this review, all aspects of application of paper substrates in potentiometry will be critically discussed. Those will include the application of paper substrates in paper-based sampling, fabrication of paper-based ion-selective and reference electrodes, and paper-based potentiometric devices. Image 1 • All aspects of paper substrates application in potentiometry are critically discussed. • Microfluidic paper-based solution sampling is reviewed. • Paper-based ion-selective and reference electrodes are discussed. • All-integrated paper-based potentiometric devices are evaluated. [ABSTRACT FROM AUTHOR]

The numerous advantages of disposable and screen-printed electrodes (SPEs) particularly in terms of portability, sensibility, sensitivity and low-cost led to the massive application of these electroanalytical devices. To limit the electronic waste and recover precious materials, new recycling processes were developed together with alternative SPEs fabrication procedures based on renewable, biocompatible sources or waste materials, such as paper, agricultural byproducts or spent batteries. The increased interest in the use of eco-friendly materials for electronics has given rise to a new generation of highly performing green modifiers. From paper based electrodes to disposable electrodes obtained from CD/DVD, in the last decades considerable efforts were devoted to reuse and recycle in the field of electrochemistry. Here an overview of recycled and recyclable disposable electrodes, sustainable electrode modifiers and alternative fabrication processes is proposed aiming to provide meaningful examples to redesign the world of disposable electrodes. Image 1 • An overview of renewable disposable electrodes from paper-based and CDtrodes to plastic waste-based SPEs is provided. • Greener routes to the synthesis of electrode modifiers or the realization of disposable electrodes are described. • Recycling strategies and waste disposal must be integral part of this new outlook on sensors and biosensor development. [ABSTRACT FROM AUTHOR]

A breathable and wearable self‐charging power system is developed by integrating paper‐based triboelectric nanogenerator (P‐TENG) and supercapacitor (P‐SC). The felt side and wire side of highly porous and mechanically robust air‐laid paper are utilized as the triboelectric pair of the P‐TENG, which not only shows remarkable flexibility and cloth‐like air permeability (333 mm s−1), but exhibits exceptional wet stability (85% voltage retention after four soaking cycles). To match the triboelectric output, the self‐discharge behavior of the P‐SC is comprehensively evaluated for effectively storing the triboelectricity. The service behavior of the self‐charging system is investigated when the P‐TENG is immersed in water or subject to partial damage. Considering the cost‐effective materials and scalable process for the fabrication of the self‐charging power units, a promising approach for the development of wearable self‐powered electronics is provided here. [ABSTRACT FROM AUTHOR]

The need for agile and proper identification of drugs of abuse has encouraged the scientific community to improve and to develop new methodologies. The drug lysergic acid diethylamide (LSD) is still widely used due to its hallucinogenic effects. The use of voltammetric methods to analyze narcotics has increased in recent years, and the possibility of miniaturizing the electrochemical equipment allows these methods to be applied outside the laboratory; for example, in crime scenes. In addition to portability, the search for affordable and sustainable materials for use in electroanalytical research has grown in recent decades. In this context, employing paper substrate, graphite pencil, and silver paint to construct paper-based electrodes is a great alternative. Here, a paper-based device comprising three electrodes was drawn on 300 g/m 2 watercolor paper with 8B pencils, and its efficiency was compared to the efficiency of a commercially available screen-printed carbon electrode. Square wave voltammetry was used for LSD analysis in aqueous medium containing 0.05 mol/L LiClO 4 . The limits of detection and quantification were 0.38 and 1.27 μmol/L, respectively. Both electrodes exhibited a similar voltammetric response, which was also confirmed during analysis of a seized LSD sample, with recovery of less than 10%. The seized samples were previously analyzed by GCMS technique, employing the full scan spectra against the software spectral library. The electrode selectivity was also tested against 3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine. It was possible to differentiate these compounds from LSD, indicating that the developed paper-based device has potential application in forensic chemistry analyses., (© 2020 American Academy of Forensic Sciences.)

A liquid metal based electronic ink is developed by mixing GaIn alloy with Ni powders. The material exhibits significantly superior adhesivity to paper and other various substrates, which guarantees stable and flexible electrical connection via direct writing. More details can be found in the article number 1800571 by Hao Chang, Qian Wang, Wei Rao, and co‐authors. [ABSTRACT FROM AUTHOR]

Liquid metals such as gallium and its alloys can be printed on various substrates to form electronic circuits. However, up to now there are still few methods for the direct writing of liquid metals on common printed paper. Here, a novel conductive material prepared by adding metal powder to a gallium alloy is introduced. The proposed material exhibits low liquidity, excellent plasticity, significantly enhanced adhesivity to paper substrates, which guarantee the stable and flexible electrical connection. The oxide film wrapping the nickel powder forms a skeleton for additional oxidation products, resulting in superior adhesion to paper. In addition, several paper flexible electronic applications are showcased to demonstrate the practical value and reparability of this material. This work paves the way for the design of a facile method of preparing paper electronics. Liquid metals usually have poor wettability with printed paper. Here, mixture of nickel powder and EGaIn alloy (GIN) made by mixing EGaIn and nickel powder has low liquidity, excellent plasticity, and significantly enhanced adhesivity to paper substrates. Especially, an electrode cut by a sharp knife can be fixed simply. The superior and rapid repairable capability demonstrates the great potential of GIN material for practical application. [ABSTRACT FROM AUTHOR]