Conducting Polymer Nanostructures Research Articles

Advancements in nanohybrids: From coordination materials to flexible solar cells

This comprehensive review explores the forefront of nanohybrid materials, focusing on the integration of coordination materials in various applications, with a spotlight on their role in the development of flexible solar cells. coordination material-based nanohybrids, characterized by their unique properties and multifunctionality, have garnered significant attention in fields ranging from catalysis and sensing to drug delivery and energy storage. the discussion investigates the synthesis methods, properties, and potential applications of these nanohybrids, underscoring their versatility in materials science. Additionally, the review investigates the integration of coordination nanohybrids in perovskite solar cells (PSCs), showcasing their ability to enhance the performance and stability of next-generation photovoltaic devices. the narrative further expands to encompass the synthesis of luminescent nanohybrids for bioimaging purposes and the development of layered two-dimensional (2D) material-based nanostructured hybrids for energy storage and conversion. the exploration culminates in an examination of the synthesis of conductive polymer nanostructures, elucidating their potential in drug delivery systems. lastly, the article discusses the cutting-edge realm of flexible solar cells, emphasizing their adaptability and lightweight design. Through a systematic examination of these diverse nanohybrid materials, this review sheds light on the current state of the art, challenges, and prospects, providing valuable insights for researchers and practitioners in the fields of materials science, nanotechnology, and renewable energy.

Controlled Synthesis of Polyaniline-Based Nanomaterials with Self-Assembly and Interface Manipulation.

Versatile nanostructures of conducting polymers are highly relevant based on unique properties, including electrical, optical, and thermal, with changes in morphology. This contribution reports a facile and reproducible synthesis approach for the design of conducting polymer nanostructures from zero- to three-dimensional composites. Two polymerization steps, namely, self-assembly-directed and interface thin layer-templated polymerizations in this synthesis, were kinetically controlled to fabricate such nanostructures directly. The uniquely designed bicontinuous nanoreactor offers an easy synthesis technique for fabricating 3D multifunctional conducting polymer composites. Self-assembly-directed polymerization could be controlled to form nanorods and further directed to form nanobowl/hollow spherical structures. The interface thin layer template process was tuned to produce hollow spherical and 2D film nanostructures. Kinetic control of polymerization was able to provide access to unprecedented nanostructures of the conducting polymers ranging from DNA origami to gecko-inspired nanostructures, with potential applications in drug delivery, energy storage, and adhesive materials. For example, this is the first conducting polymer material that can demonstrate similar adhesiveness (around 8 N/cm2) to gecko finger hairs.

Conducting polymer hollow nanostructures by surfactant-free Ouzo emulsion for an exceptional EMI shielding performance

Hollow or partially collapsed bowls of conducting polymers, such as poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (Ppy), polyaniline (PANI), and polythiophene (PT), have successfully been synthesized by surfactant-free Ouzo emulsion. The stable Ouzo region has been identified based on three-component phase diagram of FeCl3·6H2O as an oxidant, acetone as solvent, and toluene as anti-solvent, respectively. The solvent/oxidant mixture forms emulsion droplets in anti-solvent medium spontaneously without any surfactant. It is the very first report on the generation of Ouzo state in the chemical oxidative polymerization systems of conducting polymers. Cast thin film of the synthesized conducting polymer hollow nanostructures was infiltrated with commercial PEDOT:PSS solution for the formation of composite structures, where the highly conductive networks of PEDOT:PSS ensures electrical conductivity. In the meanwhile, the embedded hollow nanostructures enable multiple scattering of incident electromagnetic wave. A thin (∼6 μm) composite film shows exceptional electromagnetic interference (EMI) shielding effectiveness of ∼75 dB in X-band (8–12 GHz). Furthermore, thanks to low density of hollow conducting polymer nanostructures, thickness-normalized specific shielding effectiveness (SSE/t) shows the highest value compared to other materials published in literature. The hollow nanostructures of conducting polymers, formed using surfactant-free Ouzo emulsion, may find broader applications thanks to its simple and contaminant-free nature.

Non-Enzymatic Electrochemical Sensors for Accurate and Accessible Uric Acid Detection

Gout arthritis, a painful condition characterized by the accumulation of uric acid (UA) crystals in the joints, necessitates the development of efficient and accessible diagnostic methods. In this study, we present the design and fabrication of non-enzymatic electrochemical sensors based on molecularly imprinted conducting polymer nanostructures for the selective detection and monitoring of UA. To overcome the limitations of current point-of-care (POC) diagnostics, we developed a disposable voltammetric sensor capable of selectively and accurately analyzing UA concentrations at room temperature and pH 7.4. The sensor utilizes a selective polythiophene layer, deposited on disposable screen-printed electrodes, for the reversible binding and recognition of UA. Extensive electrochemical measurements employing electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) demonstrate excellent UA sensing performance in the wider concentration range of 1–500 μM using a standard redox solution with 2.91 μA cm−2·μM−1 sensitivity, 354 nM detection limit, and substantial selectivity over common interferents. The sensor is capable of analyzing complex mixtures such as human saliva with 90.4% recovery of the spiked UA concentration. This highly sensitive and cost-efficient electrochemical sensor offers great promise for POC testing, disease monitoring, and predicting treatment outcomes related to gout arthritis.

Role of Efficient Charge Transfer at the Interface between Mixed-Phase Copper-Cuprous Oxide and Conducting Polymer Nanostructures for Photocatalytic Water Splitting.

Photocatalytic hydrogen generation from water splitting is regarded as a sustainable technology capable of producing green solar fuels. However, the low charge separation efficiencies and the requirement of lowering redox potentials are unresolved challenges. Herein, a multiphase copper-cuprous oxide/polypyrrole (PPy) heterostructure has been designed to identify the role of multiple oxidation states of metal oxides in water reduction and oxidation. The presence of a mixed phase in PPy heterostructures enabled an exceptionally high photocatalytic H2 generation rate of 41 mmol h-1 with an apparent quantum efficiency of 7.2% under visible light irradiation, which is a 7-fold augmentation in contrast to the pure polymer. Interestingly, the copper-cuprous oxide/PPy heterostructures exhibited higher charge carrier density, low resistivity, and 6 times higher photocurrent density compared to Cu2O/PPy. Formation of a p-p-n junction between polymer and mixed-phase metal oxide interfaces induce a built-in electric field which influences directional charge transfer that improves the catalytic activity. Notably, photoexcited charge separation and transfer have been significantly improved between copper-cuprous oxide nanocubes and PPy nanofibers, as revealed by femtosecond transient absorption spectroscopy. Additionally, the photocatalyst demonstrates excellent stability without loss of catalytic activity during cycling tests. The present study highlights a superior strategy to boost photocatalytic redox reactions using a mixed-phase metal oxide in the heterostructure to achieve enhanced light absorption, longer charge carrier lifetimes, and highly efficient photocatalytic H2 and O2 generation.

Nanostructured Conducting Polymers and Their Applications in Energy Storage Devices.

Due to the energy requirements for various human activities, and the need for a substantial change in the energy matrix, it is important to research and design new materials that allow the availability of appropriate technologies. In this sense, together with proposals that advocate a reduction in the conversion, storage, and feeding of clean energies, such as fuel cells and electrochemical capacitors energy consumption, there is an approach that is based on the development of better applications for and batteries. An alternative to commonly used inorganic materials is conducting polymers (CP). Strategies based on the formation of composite materials and nanostructures allow outstanding performances in electrochemical energy storage devices such as those mentioned. Particularly, the nanostructuring of CP stands out because, in the last two decades, there has been an important evolution in the design of various types of nanostructures, with a strong focus on their synergistic combination with other types of materials. This bibliographic compilation reviews state of the art in this area, with a special focus on how nanostructured CP would contribute to the search for new materials for the development of energy storage devices, based mainly on the morphology they present and on their versatility to be combined with other materials, which allows notable improvements in aspects such as reduction in ionic diffusion trajectories and electronic transport, optimization of spaces for ion penetration, a greater number of electrochemically active sites and better stability in charge/discharge cycles.

Conducting Polymer Nanocomposite for Energy Storage and Energy Harvesting Systems

Conducting polymers (CPs) have received a lot of attention because of their unique advantages over popular materials, such as universal and tunable electrical conductivity, simple invention approach, high mechanical strength, low weight, low price, and ease of processing. Polymer nanocomposites have been enthusiastically explored as superlative energy generators for low-power-consuming electronic strategies and confirmed progressive surface area, electronic conductivity, and amazing electrochemical behaviour through expanding the opportunity of utilization. The hybridization of conducting polymer with inorganic hybrid and organic nanomaterials also resulted in multifunctional hybrid nanocomposites with better capabilities in a variety of devices, including sensors, energy storage, energy harvesting, and defensive devices. The capability and assistance of modern advancements for the development of multifunctional nanomaterials/nanocomposites have been presented, as well as the approaches for producing nanostructured CPs. The mechanisms underlying their electrical conductivity, and ways for modifying their properties, are investigated. The ongoing research towards generating superior CP-based nanomaterials is also discussed. This assessment focuses on the important schemes involved in the scientific and industrial use of polymeric materials and nanocomposites intended for the scheme and manufacture of energy strategies such as solar cells, rechargeable batteries, supercapacitors, and energy cells, as well as the waiting problems and their prospects.

Conducting Polymer‐Based Micro‐ and Nano‐batteries for Biomedical Applications: A Short Review

AbstractCurrent advancements in nanotechnology focus on miniaturization of electronic devices to provide power on demand. The Li+ ion based micro/nano‐batteries are excellent candidates for this purpose. However, the manufacture a single nano‐battery with assured reliable performance is one of the greatest challenges faced in the fabrication of Li+ ion based nano‐batteries. Nanostructured conducting polymers (NCPs) have shown promise in many frontier areas such as biosensors, microelectronics, polymer batteries, actuators, energy conversion etc. The combination of NCPs with inorganic compounds for designing nano‐batteries has been the subject of extensive investigation due to synergistic interaction of NCPs with inorganic compounds that provides remarkable improvement in electrode lifetime, rate capabilities, and voltage as well as mechanical and thermal stability. The present mini review deals with the fabrication of nano‐batteries using polypyrrole (PPy), polyaniline (PANI), and polythiophene (PTh) which could be utilized for various biomedical applications. The design and development of nano‐batteries using NCPs is discussed along with their applications in implantable devices, pace makers, smart sensing devices etc.

Detection of Galactose and Glycerophospholipids by Galactose Biosensors and Advancement Their Proficiency Using Berkelium Colloidal Nanoparticles and Poly(3,4-Ethylenedioxythiophene)-Poly(Styrenesulfonate)-Based Biosensors

In the current paper, galactose-oxidase enzyme is used as stabilization medium due to its more proficiency, ability for more accurate controlling the enzyme reaction, protecting against wasting of enzyme as well as simple and easy use and exchange of enzyme medium after performing some levels of surface modification and developing multi-walled carbon nanotubes (MWCNTs) on Berkelium plate. For better connecting and stabilizing the enzyme on the medium, the prepared medium is washed by high concentration sulfuric acid and nitric acid and a large volume of deionized water and for protecting enzyme from devastating effect of Berkelium and prohibiting them to become inactive, surface is covered with cystamine before stabilization. Regarding the large size of galactose-oxidase enzyme compared to surface of medium, a connective material with amid at one end and pyrine at the other end is used as transfer agent and for stabilizing this connection, the prepared medium is placed into dimethylformamide (DMF) solution for a couple of hours. Activity of stabilized enzyme at 460 (nm) wavelength recorded by spectroscope was depicted against time to evaluate its stability in various times. The prepared medium, which have a large amount of galactose-oxidase enzyme, can be used as electrode in sensors. Furthermore, galactose-oxidase electrochemical sensor is one of the best methods for detecting low amount of galactose and applying Berkelium colloidal nanoparticles as a supplementary material in the structure of biosensor can be effective for advancement its proficiency and optimum proficiency. On the other hand, in the current study, electrode biosensor entitled as modified carbon paste electrode with Berkelium colloidal nanoparticles (Bknano/CPE) is produced by carbon graphite powder, paraffin oil and Berkelium colloidal nanoparticles (24 nm) and it is compared with carbon paste electrode (CP). In semi-permeable membranes, a combination of 1 (ml) of 0.1 (M) phosphate buffer with specified pH and 10 (mg) of galactose-oxidase enzyme is placed around each electrode. In the same potential of 0.7 (V), biosensors are tested with galactose in concentration range of (0-1) (mM) and various amounts of pH (4,6,8) which lead to producing the maximum current and tracing galactose in pH=6 and concentration of 1 (M) as the optimum condition. Currentmetry induced from both biosensors are compared and it is confirmed that using Berkelium colloidal nanoparticles in the structure of (Bknano/CPE) electrode leads to increasing the conductivity and currentmerty of biosensor. In addition, qualitative and quantitative measurement of food components is of great importance due to high cost of traditional methods, in addition to tendency for more accurate and sensitive detecting of these components. galactose and glycerophospholipids are such compounds that they frequently measure. Various methods are used to detect these food elements. However, the necessity for accurate measurement of these two compounds with high sensitivity, especially for food health issue, leads to developing biological methods, especially biosensors. Among them, biosensors based on conductive polymer nanostructures, especially Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), have been recently interested due to their unique characteristics. The current paper aims to introduce and investigate the previously performed studies about Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)-based biosensors for detecting galactose and glycerophospholipids.

Nanostructured conductive polymer shield for highly reversible dendrite-free zinc metal anode

Zinc ion batteries (ZIBs) are promising candidates for application in next-generation energy storages because of their high capacity, low cost, and safety. However, structural issues such as irregular Zn growth, volume change, and electrochemical issues (side reactions and byproducts) hinder their practical application. Herein, we present an innovative method to develop a nanostructured conductive polymer shield for a Zn anode, which leads to an efficient and reversible ZIBs. The direct and spontaneous deposition of nanostructured conductive polymer on a Zn surface plays vital role of mechanical and electrochemical shield for Zn anode. The 3D-PPy@Zn anodes display high symmetric cycling stability for up to 1500 h at 1 mA cm−2, and the full cell assembled with a MnO2 cathode exhibits highly reversible battery performance.

Synthesis of Fructose Biosensors and Progressing Their Efficiency Using Californium Colloidal Nanoparticles for Detecting Fructose and Triglycerides

In the current paper, fructose–oxidase enzyme is used as stabilization medium due to its more efficiency, ability for more accurate controlling the enzyme reaction, protecting against wasting of enzyme as well as simple and easy use and exchange of enzyme medium after performing some levels of surface modification and developing multi–walled carbon nanotubes (MWCNTs) on Californium plate. For better connecting and stabilizing the enzyme on the medium, the prepared medium is washed by high concentration sulfuric acid and nitric acid and a large volume of deionized water and for protecting enzyme from devastating effect of Californium and prohibiting them to become inactive, surface is covered with cystamine before stabilization. Regarding the large size of fructose–oxidase enzyme compared to surface of medium, a connective material with amid at one end and pyrine at the other end is used as transfer agent and for stabilizing this connection, the prepared medium is placed into dimethylformamide (DMF) solution for a couple of hours. Activity of stabilized enzyme at 460 (nm) wavelength recorded by spectroscope was depicted against time to evaluate its stability in various times. The prepared medium, which have a large amount of fructose–oxidase enzyme, can be used as electrode in sensors. Furthermore, fructose–oxidase electrochemical sensor is one of the best methods for detecting low amount of fructose and applying Californium colloidal nanoparticles as a supplementary material in the structure of biosensor can be effective for progressing its efficiency and optimum efficiency. On the other hand, in the current study, electrode biosensor entitled as modified carbon paste electrode with Californium colloidal nanoparticles (Cfnano/CPE) is produced by carbon graphite powder, paraffin oil and Californium colloidal nanoparticles (24 nm) and it is compared with carbon paste electrode (CP). In semi–permeable membranes, a combination of 1 (ml) of 0.1 (M) phosphate buffer with specified pH and 10 (mg) of fructose–oxidase enzyme is placed around each electrode. In the same potential of 0.7 (V), biosensors are tested with fructose in concentration range of (0−1) (mM) and various amounts of pH (4,6,8) which lead to producing the maximum current and tracing fructose in pH=6 and concentration of 1 (M) as the optimum condition. Currentmetry induced from both biosensors are compared and it is confirmed that using Californium colloidal nanoparticles in the structure of (Cfnano/CPE) electrode leads to increasing the conductivity and currentmerty of biosensor. In addition, qualitative and quantitative measurement of food components is of great importance due to high cost of traditional methods, in addition to tendency for more accurate and sensitive detecting of these components. Fructose and triglycerides are such compounds that they frequently measure. Various methods are used to detect these food elements. However, the necessity for accurate measurement of these two compounds with high sensitivity, especially for food health issue, leads to developing biological methods, especially biosensors. Among them, biosensors based on conductive polymer nanostructures, especially Polypyrrole and Polythiophene, have been recently interested due to their unique characteristics. The current paper aims to introduce and investigate the previously performed studies about Polypyrrole and Polythiophene–based biosensors for detecting fructose and triglycerides.

Application of Conducting Polymer Nanostructures to Electrochemical Biosensors.

Over the past few decades, nanostructured conducting polymers have received great attention in several application fields, including biosensors, microelectronics, polymer batteries, actuators, energy conversion, and biological applications due to their excellent conductivity, stability, and ease of preparation. In the bioengineering application field, the conducting polymers were reported as excellent matrixes for the functionalization of various biological molecules and thus enhanced their performances as biosensors. In addition, combinations of metals or metal oxides nanostructures with conducting polymers result in enhancing the stability and sensitivity as the biosensing platform. Therefore, several methods have been reported for developing homogeneous metal/metal oxide nanostructures thin layer on the conducting polymer surfaces. This review will introduce the fabrications of different conducting polymers nanostructures and their composites with different shapes. We will exhibit the different techniques that can be used to develop conducting polymers nanostructures and to investigate their chemical, physical and topographical effects. Among the various biosensors, we will focus on conducting polymer-integrated electrochemical biosensors for monitoring important biological targets such as DNA, proteins, peptides, and other biological biomarkers, in addition to their applications as cell-based chips. Furthermore, the fabrication and applications of the molecularly imprinted polymer-based biosensors will be addressed in this review.

Preparation of RGO / Conductive Polymer Nanostructures and Application of Their Supercapacitors

Reduction of the nanocomposite of the conductive polymer composite in the GO/conductive polymer and the RGO imparts excellent mechanical, thermal, electrical and electrochemical properties to the composite. Therefore, the RGO/conductive polymer has become the main research direction of new functional materials. The polypyrrole/GO composite was prepared by in-situ polymerization using graphene oxide as the matrix and polypyrrole as the guest of the difference layer. The additive type, the mass fraction of GO emulsion, the molar ratio of NaOH to pyrrole, the molar ratio of oxidant to FeCl3 to pyrrole and the reaction temperature were investigated systematically for polypyrrole/GO. The influence of the structure and properties of GO composites. The supercapacitors properties of nanocomposites as electrodes were investigated.

Photoinduced atom transfer radical polymerization of methyl methacrylate with conducting polymer nanostructures as photocatalyst

Light-mediated control/living radical polymerization (CLRP) provides a convenient method to synthesize polymers with controlled molecular weight and narrow molecular weight distribution. However, high-energy wavelengths (such as UV light) and blue light are needed to initiate the polymerization, leading to unwanted side reactions. To overcome these defects, the use of long-wavelength light for light-mediated CLRP is highly desirable. In this work, photoinduced atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was successfully carried out for the synthesis of polyMMA (PMMA) with predictable molecular weights (Mn,GPC) and narrow molecular weight distribution (Mw/Mn). This was achieved using one-dimensional nanopoly(diphenyl butadiyne) (nanoPDPB) as photocatalyst, which activated the dormant alkyl bromides initiator to reversibly produce propagating radicals at ambient temperature. Initiation and termination of polymerization were regulated by periods of light. The polymerization of MMA was accomplished by the radicals generated in the redox reaction of nanoPDPB with EBP. Both 1H nuclear magnetic resonance (1H NMR) spectroscopy and chain-end extension polymerization show highly preserved bromine chain-end functionality in the synthesized PMMA. nanoPDPB displays remarkable photophysical properties in the visible light region. The polymerization of MMA followed the first-order kinetics and the evolution of the Mn,GPC versus monomer conversion and Mw/Mn demonstrated the well-controlled polymerization process. The living character of heterogeneous photomediated ATRP with nanoPDPB as photocatalyst was successfully confirmed.

Tunable Three-Dimensional Nanostructured Conductive Polymer Hydrogels for Energy-Storage Applications.

Three-dimensional (3D) nanostructured conducting polymer hydrogels represent a group of high-performance electrochemical energy-storage materials. Here, we demonstrate a molecular self-assembly approach toward controlled synthesis of nanostructured polypyrrole (PPy) conducting hydrogels, which was "cross-linked" by a conjugated dopant molecule trypan blue (TB) to form a 3D network with controlled morphology. The protonated TB by ion bonding aligns the free sulfonic acid groups into a certain spatial structure. The sulfonic acid group and the PPy chain are arranged by a self-sorting mechanism to form a PPy nanofiber structure by electrostatic interaction and hydrogen bonding. It is found that PPy hydrogels doped with varying dopant concentrations and changing dopant molecules exhibited controllable morphology and tunable electrochemical properties. In addition, the conjugated TB dopants promoted interchain charge transport, resulting in higher electrical conductivity (3.3 S/cm) and pseudocapacitance for the TB-doped PPy, compared with PPy synthesized without TB. When used as supercapacitor electrodes, the TB-doped PPy hydrogel reaches maximal specific capacitance of 649 F/g at the current density 1 A/g. The result shows that PPy nanostructured hydrogels can be tuned for potential applications in next-generation energy-storage materials.

Conducting Polymer Nanostructures and their Derivatives for Flexible Supercapacitors

AbstractThis review provides a brief summary of the recent research developments in the fabrication and application of conducting polymer nanostructures and their derivatives as electrodes for flexible supercapacitors (SCs). By controlling the nucleation and growth process of polymerization, conducting polymers (CPs) with different nanostructures can be prepared by employing chemical polymerization, electrochemical polymerization and photo‐induced polymerization. These CPs (such as polyaniline and polypyrrole) with special nanostructures possess high capacitance, superior rate capability ascribed to large electrochemical surface, and optimal ion diffusion path in the ordered nanostructures. The composites of nano‐structured conducting polymer and some conductive flexible substrates (such as carbon nanotube film and graphene film) are proved to be ideal electrode materials for high performance flexible SCs. Furthermore, high N‐containing CPs are very prospective for preparing N‐doped carbon materials used as flexible electrodes for flexible SCs. With respect to the extra pseudo‐capacitance induced by N atoms and superior stability derived from the conjugated graphitic structure of carbon materials, the obtained flexible SCs based on N‐doped carbon materials could achieve high capacitance, high rate performance, and superior cycling stability.

Superhydrophobic, superoleophobic and underwater superoleophobic conducting polymer films

From a bioinspired approach, this review reports most of the techniques used in the literature to prepare superhydrophobic, superoleophobic and underwater superoleophobic films using conducting polymers. These techniques include the formation of conducting polymer nanostructures by oxidative chemical polymerization, chemical vapor deposition, plasma deposition and electrodeposition (pre- and post-approaches). Template and templateless electrode positions are also reported. Compared to other materials, conducting polymers have unique optoelectronic properties making them sensitive to various stimuli and have, for example, very interesting applications in optical devices, sensors and oil/water separation membranes.

Interpenetrating Network Hydrogels based on Nanostructured Conductive Polymers for Flexible Supercapacitor

Flexible conductive polymer hydrogels are unique material that synergize the features of conductive polymers and hydrogels. They are excellent candidates for the flexible supercapacitor electrodes. In this paper, flexible conductive polymer hydrogels were prepared with poly(vinyl alcohol) as soft skeleton through cyclic freezing-thawing method. Firstly, phytic acid-doped polyaniline with crosslinked network was prepared using phytic acid as the dopant and crosslinking agents. Hydrogels with interpenetrating binary network nanostructure were then formed by freezing-thawing method. The interpenetrating binary network structure endowed the hydrogel reliable mechanical properties with decent flexibility and compressive strength of 3.64 MPa. More importantly, this unique structure enable them to maintain highly specific capacitance (314 F/g at the current density of 0.5 A/g).

Highly Sensitive, Printable Nanostructured Conductive Polymer Wireless Sensor for Food Spoilage Detection

Near-field communication (NFC) labeling technology has been recently used to endow smartphones with nonline-of-sight sensing functions to improve the environment, human health, and quality of life. For applications in detecting food spoilage, the development of a sensor with high enough sensitivity to act as a switch for an NFC tag remains a challenge. In this Letter, we developed a nanostructured conductive polymer-based gas sensor with high sensitivity of Δ R/ R0 = 225% toward 5 ppm ammonia NH3 and unprecedented sensitivities of 46% and 17% toward 5 ppm putrescine and cadaverine, respectively. The gas sensor plays a critical role as a sensitive switch in the circuit of the NFC tag and enables a smartphone to readout meat spoilage when the concentration of biogenic amines is over a preset threshold. We envision the broad potential use of such intelligent sensing for food status monitoring applications in daily life, storage and supply chains.

Gaoquan Shi (1963‐2018): A Pioneer in the Chemistry of Graphene and Electrochemistry of Conjugated Polymers.

Gaoquan Shi (1963‐2018): A Pioneer in the Chemistry of Graphene and Electrochemistry of Conjugated Polymers.