rGO Layers Research Articles

A novel efficient electromagnetic absorber with MoO3@Fe2(MoO4)3 core-shell nanobelts insert in reduced graphene oxide nanosheets

A composite of MoO3@Fe2(MoO4)3 and reduced graphene oxide (rGO) (MoO3@Fe2(MoO4)3/rGO) was prepared for application as a high-efficiency electromagnetic wave (EMW) absorbing material. MoO3 acted as the core that forms a conductive network between the rGO layers and Fe2(MoO4)3 acted as the shell of the MoO3@Fe2(MoO4)3 heterostructure that consumes the incident EMW by magnetic loss. The relationship between the chemical composition, micromorphology, and absorption performance of the composite was investigated in detail. The MoO3@Fe2(MoO4)3/rGO-30 wt% composite with a thickness of 1.91 mm showed a minimum reflection loss of −71.3 dB at 14.4 GHz and an effective absorption bandwidth of up to 5.8 GHz (12.2–18.0 GHz). This study provides a new pathway for the synthesis of novel effective EMW-absorbing materials with low thickness, high strength, large bandwidth, and light weight.

Local structural investigations of graphitic ZnO and reduced graphene oxide composite

Reduced graphene oxide (rGO) assisted two-dimensional (2D) graphitic ZnO (gZnO) have been prepared and characterized by Raman, FTIR, Cross-sectional high resolution transmission electron microscopy (HRTEM) and X-ray absorption spectroscopy (XAS) techniques comprising of X-ray near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements. Raman spectroscopy and FTIR measurements suggest formation of ZnO and the same has been corroborated by XANES measurements. HRTEM and polarization dependent XANES measurements with two different sample orientations confirm the formation of gZnO/rGO sandwiched layers. Density Functional Theory simulated relaxed initial structure of bilayers of gZnO sandwiched between successive rGO layers fits the EXAFS data reasonably well, supported by formation energy calculations which indicate better stability for samples having bilayers to a few layers of gZnO between rGO layers than with monolayer. These relaxed structures also help to understand the electronic structure contributing in XANES spectrum, with the help of ligand field theory.

Strong Reduced Graphene Oxide Coated Bombyx mori Silk

AbstractBombyx mori silks possess great potential in textile industries due to the large‐scale green production. However, the demand for silks with functional as well as mechanical properties are continuously rising due to the emergence of other functional textiles. It remains a great challenge to functionalize natural silk and simultaneously improve its mechanical properties. Inspired by the relationship between natural core–sheath structure and mechanical properties of cocoon silk, the application of a thin reduced graphene oxide (rGO) layer coated B. mori silk (GS) is shown via hydrogen interfacial interaction. The resultant rGO‐coated silk exhibits a remarkable tensile strength of 1137.7 MPa and toughness of 304.5 MJ m−3, which are 1.9 and 2.6 times higher than that of pure B. mori silk, respectively. Moreover, the GS shows a high electrical conductivity of 0.37 S m−1 with great thermal and deformation sensitivity. The bioinspired approach provides a universal and facile strategy for functionalizing natural fibers by applying rGO nanosheets surface coating.

Superhydrophobic and high-performance wood-based piezoresistive pressure sensors for detecting human motions

To promote the sustainable development of modern society, the functional wood-based materials have been one of the most promising candidates to alleviate the deterioration of environment by partially replacing the polymer materials derived from petroleum. However, the hydrophilicity of natural wood greatly limited its practical applications. Herein, a superhydrophobic and conductive wood sponge (P-rGO@WS) for piezoresistive pressure senor is fabricated through chemical treatment, coverage and reduction of graphene oxide (GO) and subsequent modification by polydimethylsiloxane (PDMS). The wood-based sensor exhibits high sensitivity up to 4.93 kPa−1 in 0–5 kPa and a fast response time of 160 ms. Owing to the effective stress transfer by the ordered lamellar architecture with arched layers and the mechanical compressibility improved by the rGO and PDMS layers, the sensor maintains stable electrical response even after undergoing 1000 compression cycles at a strain of 60%, illustrating the excellent fatigue resistance. Moreover, the sensor possesses superhydrophobicity with a high water contact angle of 152° and still remains superhydrophobic state even under compression. Importantly, the sensor is successfully applied for detecting human motions including wrist pulse, voice recognition and various body activities. The findings conceivably stand out a sustainable method to fabricate high-performance piezoresistive pressure senor derived from biomass materials for wearable electronics even under humid environment.

Observation of Room‐Temperature Low‐Field Magnetoresistance in Reduced Graphene Oxide/CoFe2O4 Nanocomposites

The considerable spin diffusion length and high electron mobility of graphene at room temperature makes it a suitable candidate to improve the spin transport properties of magnetic semiconductors when incorporated in a suitable stoichiometry. Herein, an observation of room‐temperature magnetoresistance (MR) properties of reduced graphene oxide (rGO)/cobalt ferrite (CFO) nanocomposites, which are synthesized by chemical methods followed by mixing in different mass ratios, is reported. The magnetic field‐dependent electrical resistivity shows a decrease in resistivity with the increase in magnetic field from 0 to 0.5 T, representing a negative MR in our samples. The highest MR of around −1.4% is observed in the 1:1 ratio CFO and rGO nanocomposite, whereas the samples with 2:1 and 3:1 ratio show the MR of ≈−1%. In the CFO–rGO nanocomposite, the charge transport takes place mainly through the rGO layers due to the insulating nature of the CFO nanoparticles. However, the ferromagnetic moments of the CFO nanoparticles induce electron‐spin scattering during the charge transport. The reduction in electron‐spin scattering results due to the parallel alignment of the magnetic moments. The alignment of ferromagnetic moments under the external magnetic field has been further confirmed from the magnetocapacitance effect of CFO nanoparticles.

Selective ammonia sensing response of vanadium doped cerium oxide nanorods wrapped reduced graphene oxide electrodes at room temperature

• Cost effective and simple two step hydrothermal method was followed for synthesis. • Vanadium doped cerium oxide nanorods were anchored over the rGO layers. • Economically reliable printed circuit board was used as electrodes. • Fabricated electrode exhibits maximum sensitivity of 85 % towards 50 ppm of NH 3 at 40 % RH. • The lowest detection limit was 10 ppm and the electrodes have long term stability of 99 % for the period of 50 days. Drastically increasing air pollution has been perceived as a vital agitation and its detection has become an unavoidable area of interest for many researchers. Room temperature operative gas sensing electrodes with long term stability and highly selective feature are crucial to meet the miniaturization of gas sensing devices. Ammonia (NH 3 ) is an irritant gas consists of pungent odor in nature. Here, we report a synthesis method for the composite of vanadium doped cerium oxide (VCeO 2 ) wrapped reduced graphene oxide (rGO) for NH 3 sensing via two step sonication assisted hydrothermal method. The physiochemical and morphological characterization were examined well in detail. The results indicate the high crystalline VCeO 2 nanoparticles were assembled as nanorods over the rGO sheets in a regular manner. The chemically active defect sites on the rGO sheets enhance the gas molecule adsorption and provide high electrical conductivity. This sensing electrode was exposed towards various target gases and it offered excellent selectivity and good sensitivity of 85 % towards 50 ppm of NH 3 with response time 104 s and recovery time 47 s. In addition, this electrode maintains 99 % of its initial sensitivity after 50 days which proves its high stability due to the room temperature operation. This prepared composite material will be a good candidate against NH 3 detection.

Robust Electrodes for Flexible Energy Storage Devices Based on Bimetallic Encapsulated Core-Multishell Structures.

Developing flexible electrodes with high active materials loading and excellent mechanical stability is of importance to flexible electronics, yet remains challenging. Herein, robust flexible electrodes with an encapsulated core‐multishell structure are developed via a spraying‐hydrothermal process. The multilayer electrode possesses an architecture of substrate/reduced graphene oxide (rGO)/bimetallic complex/rGO/bimetallic complex/rGO from the inside to the outside, where the cellulosic fibers serve as the substrate, namely, the core; and the multiple layers of rGO and bimetallic complex, are used as active materials, namely, the shells. The inner two rGO interlayers function as the cement that chemically bind to two adjacent layers, while the two outer rGO layers encapsulate the inside structure effectively protecting the electrode from materials detachment or electrolyte corrosion. The electrodes with a unique core‐multishell structure exhibit excellent cycle stability and exceptional temperature tolerance (−25 to 40 °C) for lithium and sodium storage. A combination of experimental and theoretical investigations are carried out to gain insights into the synergetic effects of cobalt‐molybdenum‐sulfide (CMS) materials (the bimetallic complex), which will provide guidance for future exploration of bimetallic sulfides. This strategy is further demonstrated in other substrates, showing general applicability and great potential in the development of flexible energy storage devices.

Determination of doxorubicin by reduced graphene oxide/gold/polypyrrole modified glassy carbon electrode: A new preparation strategy

In this paper, an electrochemical sensor was developed based on the reduced graphene oxide (rGO)/gold (Au) nanoparticles/polypyrrole (PPy)/nanocomposite modified glassy carbon electrode (GCE) for determination of doxorubicin (DOX). To do this, pyrrole monomer was in-situ polymerized on the surface of rGO/Au modified electrode. The characterization results indicated on incorporation of Au and PPy among the rGO layers enhanced the conductivity and electron transfer properties of electrode. Respect to electrochemical properties and characterization analyses, the Au and pyrrole concentrations in the producing procedure were optimized.Electrochemical investigations revealed that a process involving the same number of protons and electrons during the electrooxidation reaction was taken place. The optimum pH was determined as 5.5. Also, electrochemical reaction followed by a homogenous chemical reaction and it was a surface-controlled quasi-reversible process. The modified electrodes exhibited a high sensitivity of 185 μA mM−1 and low detection limit of 0.02 μM with a wide linear range of 0.02 μM–25 mM. Additionally, the sensor exhibited excellent reproducibility and stability properties.

Highly responsive ZnO nanorods array ultraviolet photodetectors modificated with reduced graphene oxide layer

In this paper, we demonstrate a new heterojunction ultraviolet (UV) photodetector in a superstrate configuration, i.e. glass/FTO/ZnO NRs/rGO/Au, constructed via the dip-coated method to form reduced graphene oxide (rGO) layer on the surface of ZnO nanorod arrays (NRs). The rGO compensates for surface oxygen vacancies by the oxygen-containing groups and improves the crystal properties of ZnO NRs after annealing. Furthermore, the carrier mobility and work function are effectively increased after Au doping. Under UV irradiation, the electron–hole pairs generated by ZnO NRs are separated with bias voltage, and the electrons and holes are collected via fluorine-doped tin dioxide (FTO) and rGO/Au, respectively. The rGO acts as a hole transport layer, which reduces the recombination of carriers and increases the current density, giving rise to a higher responsivity (67.48 A W−1 at −1.5 V bias) than pure ZnO NRs photodetectors.

Photo‐Triggered Shape Reconfiguration in Stretchable Reduced Graphene Oxide‐Patterned Azobenzene‐Functionalized Liquid Crystalline Polymer Networks

AbstractIn recent years, the “Kirigami” have been exploited to engineer stretchable electronics that exhibit enhanced deformability without sacrificing their mechanical and electrical properties. However, kirigami‐inspired engineering is often limited to passive mechanical stretching for 3D shape morphing. To counter this problem, in this study, azobenzene‐functionalized liquid crystalline polymer networks (azo‐LCNs) are monolithically integrated with patterned reduced graphene oxide (rGO), called azo‐LCN/rGO, to achieve on‐demand shape reconfiguration in response to external stimuli (UV, NIR, solar rays, and portable light); in addition, the azo‐LCN/rGO exhibit highly enhanced mechanical and electrical properties. The cross‐sectional area and thickness of rGO patterns are controlled using a masking technique and evaporative self‐assembly. By the spatial patterning of rGO, insulating azo‐LCNs are converted into electrically conducting structures (381.9 S cm−1). The elastic modulus of <2 µm thick azo‐LCN can be tailored in the range of 1.3–6.4 GPa by integration with rGO layers of thickness less than 2 µm. Upon UV irradiation, azo‐LCN/rGO exhibit both for/backward in‐plane bending as well as out‐of‐plane chiral twisting, thus overcoming the typical trade‐off relationship between elastic modulus and deformability. Finally, an on‐demand contactless shape reconfiguration in azo‐LCN/rGO by UV irradiation in conjunction with passive mechanical strain is demonstrated.

E-textile based wearable thermometer from WS2-quantum dots

We report here the successful operation of WS2-QD/RGO hybrid temperature sensor, which performs instant measurement like thermometer in a wide temperature range: 77–398 K, in both static- and instant mode. All this was possible by embedding WS2-QDs on electrically conducting RGO layer, synthesized on cotton textile fabric. The device is simple, scalable, flexible and cost-effective. Successful trial to monitor human body temperature is conducted with fast response- and recovery time ∼0.60 and 11.3 s with an exceptional resolution ∼0.06 K. Crucial parameters such as temperature coefficient of resistance (TCR) and thermal hysteresis (H th) were theoretically analyzed to understand the intricate mechanism behind the working of a temperature sensor; temperature sensing data at both high- and low temperatures are outstanding as well as competitive. To mention, a few of these parameters are found comparable and even superior to some of the devices as reported. This sensor device proved its flexibility and stability under various in situ mechanical deformation tests, showing its promising potential for future generation wearable health monitoring devices. To the best of our knowledge, this is the first report on WS2 in general, and WS2-QDs, in specific, based temperature sensing device and its operational demonstration as of now.

Scanning electrochemical microscopy and electrochemical impedance spectroscopy-based characterization of perforated polycarbonate membrane modified by carbon-nanomaterials and glucose oxidase

In this research, scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS) were applied for the evaluation of surface characteristics of electrochemical (amperometric) biosensor based on two composite structures consisting of perforated polycarbonate membrane modified by carbon-nanomaterials and glucose oxidase. The first structure consisted of the polycarbonate filter membrane, punctured by 400 nm holes (PCM) consequently modified with single walled carbon nanotubes (SWCNT) and graphene oxide (GO) layer (PCM/SWCNT/GO); and the other structure consisted of the same PCM, consequently modified with SWCNT and reduced graphene oxide (rGO) layer (PCM/SWCNT/rGO). These two composite structures were developed and applied in biosensor design. In order to form a biosensing surfaces the PCM/SWCNT/GO and PCM/SWCNT/rGO composite structures were modified by immobilized glucose oxidase (GOx). The surface of GOx modified PCM/SWCNT/GO composite structure (PCM/SWCNT/GO/GOx) was evaluated by SECM redox-competition mode at different glucose concentrations. It was determined that PCM/SWCNT/GO/GOx composite structure is suitable for the design of amperometric glucose biosensors, because SWCNT/GO layer facilitates electron transfer from GOx via the oxidation of formed catalyzed reaction product H 2 O 2 . Therefore, the PCM/SWCNT/GO/GOx structure is a promising material for the design of amperometric glucose biosensors and biofuel cells, which are useful for a wide variety of environmental purposes and green energy production using food-industry waste. • Punctured polycarbonate membrane (PCM) was modified by single walled carbon nanotubes (SWCNT). • PCM/SWCNT-based structure was modified by graphene oxide (GO) or reduced graphene oxide (rGO). • On the surface of PCM/SWCNT/GO and PCM/SWCNT/rGO structures glucose oxidase (GOx) was immobilized. • Scanning electrochemical microscopy (SECM) and impedance spectroscopy (EIS) were applied. • It was determined that PCM/SWCNT/GO/GOx structure is suitable for the design of glucose biosensor.

Fabrication of multi-nanocavity and multi-reflection interface in rGO for enhanced EMI absorption and reduced EMI reflection

Through inserting SiO2@Au into the reduced graphene oxide (rGO) layers, the rGO-SiO2@Au composites were prepared via the vacuum-assisted electrostatic self-assembly method. The obtained composites exhibit excellent electromagnetic interference (EMI) shielding effectiveness due to the successful construction of multi-nanocavities (spherical SiO2 cavities and layered air cavities between rGO), multi-reflection interfaces (rGO and Au shell) and continuous conductive network (rGO-Au-rGO). Among them, the total shielding effectiveness (SET) of the composites with 75.78 wt% SiO2 and 19.38 wt% rGO can reach 38.4 dB at 18 GHz. Thereinto, the shielding effectiveness absorption (SEA) is 36.4 dB, 1.3 and 13.5 times higher than that of rGO and SiO2@Au. And the shielding effectiveness reflection (SER) is always below 5 dB from 1 to 18 GHz, much lower than that of rGO (about 15 dB). Further studies found that the SEA values were enhanced at 12.6 GHz and 6.2 GHz due to the construction of cavities and location of Au nanoparticles between the rGO layers. This study provides a simple and mild method to prepare high-performance thin-layered materials with applications in the field of EMI absorption shielding.

MOF derived double-carbon layers boosted the lithium/sodium storage performance of SnO2 nanoparticles

Tin oxide (SnO2) was considered as a promising alternative to commonly used graphite anode in energy storage devices thanks to its superior specific capacity. However, its electrochemical property was severely limited due to the inherent poor conductivity and drastic volume variation during the charging/discharging process. To overcome this disadvantage, we grew Sn-MOF directly on graphene oxide (GO) layers to synthesize a double carbon conductive network-encapsulated SnO2 nanoparticles (SnO2/C/rGO) via a facile solvothermal method. During the process, Sn-MOF skeleton transformed into porous carbon shells, in which nanosized SnO2 particles (~8nm) were embedded, while GO template was reduced to highly conductive rGO layer tightly wrapping the SnO2/C particles. This double-carbon structure endowed SnO2/C/rGO anode with enhanced specific capacity and rate property both in lithium ion batteries (LIB) and sodium ion batteries (SIB). The SnO2/C/rGO anode showed a highly reversible specific capacity of 1038.3 mAh g−1 at 100 mA g−1, and maintained a stable capacity of 720.2 mAh g−1 (70.1%) under 500 mA g−1 after 150 cycles in LIBs. Similarly, highly reversible capacity of 350.7 mAh g−1 (81.1%) under 100 mA g−1 after 150 cycles was also achieved in SIBs. This work provided a promising strategy in improving the electrochemical properties of SnO2 nanoparticles (NPs), as well as other potential anode materials suffering from huge volume change and poor conductivity.

Performance Improvement of n-ZnO/p-rGO Heterojunction Based Room Temperature Hydrogen Gas Sensor

This letter reports a room-temperature hydrogen gas sensor based on the nanohybrid structure of ZnO nanorods (NRs) and reduced graphene oxide (rGO) with better sensitivity. In this nanohybrid structure, ZnO NRs were grown up by the chemical bath deposition technique followed by the electrochemical exfoliation of rGO layer. The collaborative hybridization of these two dissimilar sensing elements revealed much better response at room temperature, which could hardly be achieved by the individual ones. The sensing was carried out at room temperature at ~40% RH, with hydrogen as a target gas with fastest response and recovery times (17.02 and 27.06 s), which have not been achieved earlier. The physics behind it is the high carrier mobility of rGO. A very high response magnitude (586.93% at 100 ppm) was found due to the increased number of gas-interaction sites and availability of free surface energy provided by ZnO NRs and rGO. A comparative discussion elucidating the role of ZnO NRs-rGO junctions has also been presented correlating the experimental findings.

Selective liquid chemicals on CO2 reduction by energy level tuned rGO/TiO2 dark cathode with BiVO4 photoanode

Photoelectrochemical (PEC) CO2 reduction reaction (CO2RR) has challenged a selectivity and conversion efficiency of chemical fuels resulting by the interfacial reaction on cathode itself. Herein, a reduced graphene oxide (rGO) layered TiO2 was firstly studied as dark cathode for selective production of liquid fuels, with BiVO4 photoanode. (040) crystal facet engineered BiVO4│KHCO3│rGO/TiO2 combination is introduced in this study. A different free energy level of electrons involves in CO2RR, which is controlled by band energy adjustment via varying reduction degrees of rGO layer on TiO2 electrode. The relative number and lifetimes of the excited state electrons on GO/rGO functional layer on TiO2 investigated by time-resolved photoluminescence spectroscopy. The mechanism and pathway of liquid product selectivity has been suggested based on 13C isotope labelling technique and in-situ electron paramagnetic resonance spectroscopy. Above results represent the viable strategy to get high product selectivity during artificial photosynthesis reaction.

Lithiophilic N-doped carbon bowls induced Li deposition in layered graphene film for advanced lithium metal batteries

Lithium (Li) metal with high theoretical capacity and low electrochemical potential is the most ideal anode for next-generation high-energy batteries. However, the practical implementation of Li anode has been hindered by dendritic growth and volume expansion during cycling, which results in low Coulombic efficiency (CE), short lifespan, and safety hazards. Here, we report a highly stable and dendrite-free Li metal anode by utilizing N-doped hollow porous bowl-like hard carbon/reduced graphene nanosheets (CB@rGO) hybrids as three-dimensional (3D) conductive and lithiophilic scaffold host. The lithiophilic carbon bowl (CB) mainly works as excellent guides during the Li plating process, whereas the rGO layer with high conductivity and mechanical stability maintains the integrity of the composite by confining the volume change in long-range order during cycling. Moreover, the local current density can be reduced due to the 3D conductive framework. Therefore, CB@rGO presents a low lithium metal nucleation overpotential of 18 mV, high CE of 98%, and stable cycling without obvious voltage fluctuation for over 600 cycles at a current density of 1 mA·cm−2. Our study not only provides a good CB@rGO host and pre-Lithiated CB@rGO composite anode electrode, but also brings a new strategy of designing 3D electrodes for those active materials suffering from severe volume expansion.

One-step hydrothermal synthesis and photocatalytic activity of SnO2/rGO nanocomposites: effects of pH values

In this study, tin oxide /reduced graphene oxide (SnO2/rGO) samples were prepared by hydrothermal method. The structural characteristics, phase composition, morphology, and size of the samples were studied by X-ray diffraction, Raman scattering spectroscopy, and scanning electron microscopy. Results showed that SnO2 nanoparticles had tetragonal rutile crystal structure with a size ranging from 4.65 nm to 5.77 nm when the pH was increased from 5 to 9. The SnO2 nanoparticle morphology together with rGO layers was observed in the FESEM image of these samples. The absorption spectra of SnO2/rGO samples show the characteristic absorption peak of SnO2 at 296 nm, in which the band gap value of the material decreased from 4.91 eV to 4.81 eV when pH was increased from 5 to 9. The simultaneous formation of the two phases of SnO2 and rGO was demonstrated by Raman scattering spectroscopy. Photocatalytic degradation of methylene blue reached 86% after 90 min under visible light.

Fabrication of efficient Au@TiO2/rGO heterojunction nanocomposite: Boosted photocatalytic activity under ultraviolet and visible light irradiation

In the present study, we have performed a modified solvothermal process to prepare gold-titania (Au@TiO2) binary nanocomposite anchored into reduced graphene oxide (rGO). The experimental protocol was conducted through one-pot step using only metals precursors and fresh rGO aqueous solution without recourse to added surfactants or capping agents. The DMSO was used as solvent in this solvothermal protocol. Deep techniques including X-ray diffraction powder (XRD), Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM) confirm the successful formation of this heterojunction. The ternary Au@TiO2/rGO exhibited interesting absorption of light in both UV and visible regions. Compared to pristine TiO2 and binary Au@TiO2, the ternary nanocomposite revealed high efficiency in photocatalytic decomposition of organic pollutants molecules and dyes. The increase of photocatalytic performance can be associated to the broad absorption spectrum of the ternary nanocomposite which can enhance the photogenerated electrons–holes pairs and therefore increase the photochemistry reaction at the photocatalyst surface. Moreover, the rGO layers act as outstanding electron transporter which facilitating effective separation of electron–hole pairs. The present work provides an insight into preparing of ternary nanostructures based rGO materials for photoactive UV–visible light photocatalyst.

Acetylcholinesterase sensor based on PANi/rGO film electrochemically grown on screen‐printed electrodes

AbstractIn this work, the polyaniline/reduced graphene oxide (PANi/rGO) bilayer was directly electrodeposited on carbon screen‐printed electrodes (SPE). Some details in growth of PANi/rGO bilayer were revealed from cyclic voltammograms and X‐ray photoelectron spectra. The growth of stacked rGO film at high compactness on the electrode surface is mainly accompanied with reduction of epoxy functional groups at basal planes of graphitic flakes. The as‐grown rGO layer with abundent hydroxyl functional groups at basal planes is preferable to attract intrinsic fibrillar‐like PANi polymer chains in protonated aqueous media. The as‐prepared PANi/rGO hybrid bilayer has shown good conductivity, high porosity, good adhesion to biomolecules, and fast electron transfer rate (increased by 3.8 times). Herein, PANi/rGO film has been further utilized to develop disposable acetylcholinesterase sensors able to detect acetylthiocholine (ATCh) with apparent Michaelis ‐ Menten constant of 0.728 mM. These sensors provide a very promising technical solution for in‐situ monitoring acetylthiocholine level in patients with neuro‐diseases and determination of neuro‐toxins such as sarin and pesticides.