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Establishing a sustainable energy supply is necessary for intelligent greenhouse environmental management. Compared with traditional energy, green and eco-friendly energy is more conducive to protecting the agricultural production environment. In this study, a fluorinated superhydrophobic greenhouse film is proposed as a negative triboelectric layer material for the construction of a triboelectric nanogenerator that harvests raindrop energy (RDE-TENG). Moreover, an upgraded configuration is adopted, where the bulk effect between the lower/upper electrode and film replaces the interfacial effect of the liquid-solid interface, thereby promoting charge transfer. The results show that the RDE-TENG can serve as a sustainable energy source for greenhouse temperature and humidity sensors that assists in realizing intelligent control of the environment and guides agricultural production processes. This device exhibits high-voltage and a stable output; thus, it has the potential to replace traditional energy sources, which helps toward realizing a self-powered intelligent greenhouse planting mode.

The era of the Internet of Things (IoT) requires sustainable and convenient methods to power widely distributed sensing devices. Self-powered systems have emerged as a potential solution that utilizes ambient energy from environmental sources such as electromagnetic fields, mechanical motion, solar power, and temperature gradients. Recently, the integration of wireless technologies with self-powered systems has attracted significant attention as a way to address challenges in energy harvesting and transport without the cost and inherent physical constraints of wires. This review summarizes recent progress in the application of wireless technology in self-powered systems for applications in harvesting ambient electromagnetic energy and in transferring power between devices. In addition, challenges and development trends in the future of wireless self-powered sensor networks are discussed.

The rapid progress in distributed electronics in agriculture depends on a wide range of energy supplies, such as cables and batteries. However, cable installation and maintenance are inconvenient in the agricultural environment, and the massive use of batteries will cause high replacement costs and serious environmental issues. To mitigate these problems, a water flow-driven and high-performance triboelectric nanogenerator based on agricultural debris (including derelict plant fibers and recycled greenhouse film) (AD-TENG) is developed. The precisely designed air gap and plant fiber-based dielectric brushes enable minimized frictional resistance and sustainable triboelectric charges, resulting in low damping and high performance for the AD-TENG. After nano-morphology modifications of the dielectric layer, the maximum power density of the AD-TENG increases by 64 times and reaches ≈1.24 W m

Plant nanoelectronics aims to achieve specific functions by selecting suitable nanomaterials to connect or implant into plants. In this work, a new cyclic-spraying method is developed to attain controllable growth of surface-attached metal-organic framework (SURMOF) coatings on various complex substrates, including cotton, silk, and plant leaves. The covalent bonds formed between the SURMOF layer and substrate enable them to connect firmly without additional adhesive and do not fall off from the microstructured substrate surface with the change of biological activity or environment. Noteworthily, the triboelectric polarity of SURMOF can be regulated by changing the ligand molecule. As a proof of concept, a growth-controllable triboelectric nanogenerator (GC-TENG) based on living leaves and coated SURMOF layer is developed, and the feasibility of using it in the self-driven agricultural monitoring system is explored. In addition, long-term monitoring results show that the growth of SURMOF coating will not cause damage to plant leaf tissue, nor will it affect plant photosynthesis.

The growing demand of intelligent wearable devices has triggered rapid development of highly stretchable strain sensors and power sources. Here, we fabricated a sandwich-structured stretchable device, where a composite film is encapsulated in two layers of polydimethylsiloxane (PDMS). The highly conductive composite film is composed of one-dimensional (1D) silver nanowires (AgNWs) network wrapped with two-dimensional (2D) metallic MoS2 nanosheets. The combination of 1D AgNWs and 2D metallic MoS2 nanosheets endows the composite film with excellent flexibility and conductivity, which enables their use as high-performance skin-mountable strain sensor with the maximum gauge factor of 215.4 and high stretchability up to 70%. Furthermore, the sandwich-structured device can serve as a stretchable triboelectric nanogenerator (STENG). Results show that the STENG with an area of 1 × 2.5 cm2 could produce an average power density of 0.16 W/m2. In addition, the STENG could retain stable output performance even under a stretching ratio of 50%. With the outstanding stretchability, it can be fully conformal on nonplanar irregular object such as plant leaves. Moreover, we demonstrated that the fabricated STENG could harvest wind energy and serve as a self-powered wind speed sensor when attached to plant leaves. This work provides new prospects for stretchable power sources and shows potential applications in wearable electronics.

In this work, a fully stretchable triboelectric nanogenerator (FSTENG) composed of an electrospun electrode and a porous PDMS friction layer with anti-nickel foam structure was fabricated. This FSTENG can deliver an optimal output voltage of 92 V, which is ten times greater than that of the TENG based on flat PDMS film. The superior performance is attributed to the use of anti-nickel foam structure-based porous PDMS film in FSTENG, which enhances the surface-to-volume ratio and surface roughness. Importantly, the FSTENG could maintain stable output performance even under a stretching ratio of 50%. With these excellent features, the developed FSTENG was designed as a self-driven sensor for finger bending and walking status monitoring. Furthermore, to expand the driving mode of FSTENG, FSTENG was successfully attached to the leaf for monitoring the wind speed in the natural environment without external power supply. The excellent flexibility, stretchability, and versatility of FSTENG make it as a promising self-driven sensor for human behavior and environmental monitoring.

The increasing potential of wearable electronics has been motivating the development of self-powered devices to overcome the restriction imposed by conventional power supply. Herein, a kind of highly electronegative and conducting material of MXene nanosheet has been innovatively integrated with poly(vinyl alcohol) (PVA) for electrospinning nanofibers film to fabricate flexible all-electrospun triboelectric nanogenerator (TENG). Silk fibroin (SF) was chosen for electrospinning nanofibers film to serve as electron donor for TENG with great triboelectricity and biocompatible nature. The MXene-based all-electrospun nanogenerator shows excellent stability and durability as well as extraordinary electrical performance, which supports an instantaneously maximum peak power density of 1087.6 mW/m2 as the load resistance is 5.0 MΩ. Moreover, beyond harvesting electrical power, the fabricated TENG was utilized for real-time monitoring various types of body motion. Lastly, we used the developed TENG to power electrowetting on dielectric (EWOD) chip to actuate droplet transport. Considering the excellent triboelectric performance, ease of large-scale manufacturing, and environmental friendliness, this MXene-based all-electrospun TENG provides a promising solution for developing practical, flexible, and self-powered electronic devices.

Single-walled carbon nanohorns (SWCNHs) was utilized as an ion-to-electron transducer to fabricate all-solid-state ion-selective electrodes (ISE) for the first time. To evaluate the performance of developed SWCNHs-based calcium ISE, various electrochemical experiments were carried out. A Nernstian response (29.69 ± 0.24 mV/decade, R2 = 0.9996) was acquired across a broad linear range between 10−6 and 10−2 M, and the detection limit of 10−6.1 M was achieved in the meantime. Additionally, water layer test and reversed chronopotentiometry were used to estimate the long-term and short-term stability of SWCNHs-based ISE, respectively, indicating SWCNHs is capable of enhancing potential stability on account of its hydrophobicity. Furthermore, a SWCNHs-based reference electrode (RE) was fabricated by directly coating a photo-polymerised reference membrane (RM) onto a SWCNHs modified electrode. Results demonstrated that the SWCNHs-based RE exhibited slight potential fluctuation for common ions with different charges over a wide concentration range of calibration. Based on these superior results, an integrated all-solid-state SWCNHs-based potentiometric sensing device combined SWCNHs-based ISE and SWCNHs-based RE was constructed for detecting calcium, which shows a Nernstian response with a slope of 27.14 mV/decade. This developed electrode in the aid of SWCNHs exhibits fast response as well as outstanding potential stability, making it extreme promising for routine sensing application.

Flexible sensing devices have drawn tremendous attention in the past decades due to their potential applications in future hand-held, potable consumer, and wearable electronics. Here, we firstly developed an ultrasensitive wireless potentiometric aptasensor based on flexible freestanding graphene paper for kanamycin detection. Flexible graphene paper made from a simple vacuum filtration method was used as a biocompatible platform for effective immobilization of aptamer. A nuclease-assisted amplification strategy was introduced into this potentiometric biosensing system in order to significantly improve the detection sensitivity through a classic catalytic recycling reaction of target induced by the nuclease (DNase I). As expected, an ultra-low detection limit of 30.0 fg/mL for kanamycin was achieved. Furthermore, the developed potentiometric enzymatic aptasensor exhibits high selectivity, favorable flexibility, excellent stability and reproducibility, which holds great promising for its routine sensing application.

The emerging demand for flexible, portable, easily accessible, and cost-effective electronic fabrication has motivated the development of novel techniques to manufacture electronic components and devices. Inspired by daily hand-writing, an all-written potentiometric sensor was developed by using a Chinese brush pen-based writing technique. A writing ink made from graphene nanosheet (GN) as a conductive component, Triton X-100 as a stabilizer, and xanthan gum as a binder, was used to obtain flexible electrode substrate. Results demonstrate the GN ink-based writing electrode (GN-WE) possesses good conductivity, fast electron-transfer kinetics, considerable stability, and favorable flexibility. By further writing cadmium ion selective membrane (Cd2+-ISM) and photopolymerized reference membrane (RM) on the surface of GN-WE, an all-solid-state potentiometric sensor for cadmium ion was constructed. A large bulk capacitance (41.67 μF) and excellent potential stability (drift of 0.156 mV h–1) were achieved at the...

Real-time monitoring of the wind vector, including wind speed and direction, is significant for crop management and production in agricultural environment. However, traditional wind vector sensors are difficult to meet the needs of modern sustainable agriculture due to their considerable size, low accuracy, and lack of energy supply. Hence, there is a great need for wind vector sensors that can respond super-sensitively to environmental stimuli without external power supply. Herein, a transparent and degradable hydroxyethyl cellulose film was introduced to fabricate a triboelectric nanogenerator (TENG) based on the slit effect for wind energy harvesting and self-powered wind vector monitoring. The maximum output voltage of slit-effect-enabled TENG (SE-TENG) is up to ~ 600 V under a wind speed of 7 m/s, and various agricultural sensors can be continuously driven. Furthermore, an omnidirectional wind energy harvester (OWEH) composed of eight SE-TENGs and an electrometer data-acquisition board was assembled to monitor the wind directions and speed ranging from 0.5 to 10 m/s accurately. This work poses an effective and green method for wind vector monitoring in agricultural environment and demonstrates the potential of TENG technology in intelligent agriculture.

Two kinds of two-dimensional MXene (of type Ti3C2Tx and Ti2CTx) nanosheets are described for use in solid-contact ion-selective electrodes (SC-ISEs) where they act as ion-to-electron transducers. Electrochemical characterizations show that the MXene-coated electrodes possess high double layer capacitance and enable rapid electron transport. This demonstrates the enhanced efficiency of MXene-based solid-contact layers to improve ion-electron transduction. Both Ti3C2Tx- and Ti2CTx-based SC-ISEs exhibited a Nernstian response (26.4 and 24.9 mV/decade, respectively) between 10−1 and 10–5.5 M Ca(II) concentrations with rapid response (

Agro-product safety is one of the most important topics in our daily lives, making it particularly critical to assure the quality of all consumed agro-products. Therefore, it is highly desirable to develop sensitive and stable methods to detect the contaminants in agro-products. Meanwhile, nanomaterials with outstanding properties have received widespread attention. A variety of nanomaterials have been incorporated into biosensors to realize highly sensitive, stable, and rapid detection of contaminants in agro-products, such as mycotoxins, pesticides, antibiotics, heavy metals, and microorganisms. During the past years, more potential nanomaterials with more variety of structures have been applied to develop new kinds of biosensors, and show ultra-higher sensitivity in the field of agro-product contaminant detection. This review summarizes the latest researches in the field of nanomaterial-based biosensors for agro-product contaminant detection in the past four years (2017–2020). Furthermore, the limitations analysis and research trends in this field are also provided.

Fibers with high stretchability and conductivity are considered as essential building blocks for next-generation fiber-based electronics. Herein, we presented a facile, scalable, and environmentally-friendly approach for the fabrication of multifunctional fibers. The fiber obtained by wet-spinning technology is composed of MXene and carbon nanotube (CNT) embedded in polyurethane (PU), with a cobblestone-shaped gold nanostructure (namely, AuCNS) on its surface formed by spontaneous reduction between AuCl4¯ and MXene. The fiber exhibits high conductivity and excellent durability under mechanical deformations, which makes it promising for constructing wearable fiber-based devices. The formation of AuCNS significantly enhances the surface roughness and catalytic behavior of the fiber. An ultra-sensitive pressure sensor with high sensitivity, fast response time, and excellent durability was fabricated using the fiber as sensing units. Besides, a three-electrode fiber-based flexible electrochemical sensor for highly sensitive detection of H2O2 can be designed due to the excellent electrocatalytic activity of AuCNS. The fiber can also be used as an electrode for constructing a fiber-based triboelectric nanogenerator for water energy harvesting. All these indicate that this multifunctional fiber would hold great promise in next-generation fiber-based wearable sensors as well as self-powered systems.

Two kinds of two-dimensional MXene (of type Ti

The durability issue of triboelectric nanogenerators (TENGs) still limits its practical application for long-term operation, especially in harvesting water energy, which is one of the most widespread energies in nature. Attempting to ameliorate this, fluorinated graphene (FG) with unique triboelectric negativity and superhydrophobic property is introduced to serve as a new triboelectric and protective layer for TENG construction. The self-cleaning as well as anti-corrosion property and durability of the FG coating-enabled TENG device is then demonstrated. Furthermore, this novel triboelectronegative material candidate is applied for consecutively coating on Cu mesh and the inner wall of sewage pipe to fabricate TENGs for water energy harvesting and working as a metal protective layer in the meantime. Through the extraordinary output performance, the feasibility of FG-enabled triboelectric coating to be used in the field of interference screening, filtering, and sewage pipes is proved. This developed triboelectronegative coating not only broadens the material selection of TENG but also significantly enhances the durability and robustness of TENG for water energy harvesting, which possesses great potential in applying in metal protection and water energy harvesting under extreme conditions (e.g., strong acid and strong alkaline environments).

Raining as a common phenomenon in agricultural environment sometimes may bring adverse effects on agricultural production, to remedy this, agrotextiles are extensively utilized. In this study, the technology of triboelectric nanogenerator (TENG) is firstly integrated into agrotextiles. To construct a robust TENG yarn, a facile and effective method for the fabrication of stretchable electrode is developed, i.e. coating an elastic fibre with MXene ink, followed by spontaneous growth of Ag nanoparticles (AgNPs). By consecutively coating the conductive fibre with PDMS, the final developed triboelectric yarn (diameter of ~400 μm) is demonstrated to possess extraordinary output performance, generating a voltage of 7.7 V with a effective contact length of 3 cm. Moreover, the excellent mechanical property, highly stretchability, outstanding robustness, and considerable hydrophobicity of the TENG yarn also make it be capable of being woven into net or integrated into agrotextile. Thus, in the meantime of providing protection for crop plantation and animal husbandry to improve the quality and yield of agricultural products, the raindrop energy can also be harvested. Moreover, it can also act as a self-powered sensor to monitor dynamic force, which provide a basic information of weather condition. All in all, this developed TENG yarn enables many promising advantages such as being easily engineered and scaled up, therefore possessing great potential to apply in agrotextile for building intelligent agriculture.

In recent years, the agricultural Internet of Things (IoT) has been developing rapidly, but the corresponding long-term sustainable and efficient power source for sensors in IoT is still under researching. In this work, an integrated self-cleaning and self-charging device capable of harvesting energy from the swinging crop leaves and raindrops was developed based on laser-induced graphene (LIG) technology, which consists of a multi-operating mode triboelectric nanogenerator (MTENG) and a micro-supercapacitor (MSC). Moreover, the lotus leaf-like bionic structure formed on the device surface based on the template method gives the device the characteristics of waterproof and self-cleaning, so that the device can maintain stable output in a humid environment. Outstanding flexibility, strong self-cleaning effect, stable electrical output, and high integration make this self-charging device possess the potential to replace traditional energy sources for agricultural IoT sensors.

Two-dimensional (2D) transition metal carbides and nitrides, named MXene, appear promising application prospects in sensor filed. Metal nanoparticles, especially bimetallic nanoparticles, are the superior nanocatalyst, which process excellent features due to the high specific surface area and synergistic catalytic capacity. Using ultrathin MXene nanosheets as the natural reducing agent and support, we prepare the shape-controlled Au-Pd bimetallic nanoparticles via a self-reduction process at room temperature in a short time, which can well enhance the catalytic performance and are benefit for the acetylcholinesterase immobilization. Based on their desired properties, we propose a disposable electrochemical biosensor for the detection of organophosphorus pesticide using the multi-dimensional nanocomposites (MXene/Au-Pd) as the functional platform. Under the optimized conditions, our fabricated biosensor exhibits a favorable linear relationship with the concentration of paraoxon from 0.1 to 1000¿¿g¿L¿1, with a low detection limit of 1.75¿ng L¿1. Furthermore, the biosensor can be applied for paraoxon detection in pear and cucumber samples, providing an effective and useful avenue for the applicability of novel 2D nanomaterials in biosensing field., This work was supported by the National Science Fund for Excellent Young Scholars of China (Grant No. 31922063).

The ambient dissipated energy such as the vast scale of mechanical energy in the agricultural system (e.g., leaf swing energy) and the writing motion existing extensively in our daily life are underutilized. Herein, to address these issues and overcome the limitations of conventional batteries, we fabricated a highly flexible and effective triboelectric nanogenerator (TENG) based on MXene and polydimethylsiloxane (PDMS) composite (PDMS/MXene) film and laser-induced graphene (LIG) electrode. The introduction of conductive and electronegative MXene into PDMS to fabricate porous film, not only enhances the electrical conductivity but also increases the triboelectronegativity. As a result, the output performance is significantly improved, 7-fold greater than the pure flat PDMS-based TENG. The developed TENG with excellent performance, considerable adhesion, and outstanding flexibility was successfully applied for harvesting leaf swing energy and being used as a writing board to collect writing energy. Furthermore, we developed a MXene-based TENG array acting as a self-powered sensor for handwriting recognition. In this regard, MXene-enabled TENG possesses a great promising in harvesting mechanical energy from the agricultural field (e.g., leaf swing energy) and human activities (e.g., writing), moreover, it can further be applied in writing or tactile sensing for pad, robotics, and man-machine interaction field.

Owing to their large specific surface, favorable electrical conductivity, and excellent electrocatalytic capabilities, two-dimensional transition metal dichalcogenides have received considerable attention in the field of biosensors. On the basis of these properties, we developed a portable and disposable enzyme-based biosensor for paraoxon detection using a metallic MoS2 nanosheets modified screen-printed electrode (SPE). The exfoliated ultrathin metallic MoS2 nanosheets can accelerate the electron transfer on electrode surface and contribute to the immobilization of acetylcholinesterase (AChE) via the cross-linking of glutaraldehyde. Electrodeposited gold nanoparticles (AuNPs) on SPE were used to immobilize MoS2 nanosheets through the interaction between Au atoms on AuNPs and S atoms on MoS2. Using acetylcholine as the substrate, AChE can catalyze the formation of electroactive thiocholine and further generate the redox current. In the presence of paraoxon, the activity of AChE can be inhibited, making t...

To investigate the protective effect of epigallocatechin-3 -gallate (EGCG) on apoptosis of cerebellar granule neurons (CGNs) induced by acrylamide (ACR).CGNs were cultured with the addition of 5 mmol/L ACR for 24 hours to set up a cell injury model. Prior to ACR treatment, CGNs were treated with different concentrations of EGCG (0, 5, 10, 25, 50, 100 μmol/L) for 48 hours. Neuronal viability was measured with metylthiazdyltetrazolium (MTT). The activity of SOD and the content of MDA were assayed. Hoechst33342 staining was employed to observe morphological changes of the cell nucleus. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure expression of bcl- 2 mRNA and bax mRNA.At the concentrations of 10, 25 or 50 μmol/L, EGCG played a protective role against ACRinduced CGN injury. Compared with ACR injured group (no EGCG), EGCG improved the cell viability, enhanced SOD activity, decreased the level of MDA as well as the cell apoptosis ratio (P0.05). Bcl-2 mRNA expression was increased and bax mRNA expression was reduced (P0.05). 25 μmol/L EGCG had the largest effect. However, 100 μmol/L EGCG did not have a significantly protective effect.EGCG at appropriate concentration has protective effect against the CGNs on apoptosis induced by ACR.

To investigate the effect of linear alkylbenzenesulfonate (LAS) on the reproductive capacity and life-span of Drosophila melanogaster.Drosophila melanogaster images within 8 h after eclosion were collected with ether anesthesia. The female and male of similar size and normal shape and behavior were selected. The Drosophila melanogasters were cultured in the culture medium containing LAS of different densities. We divided the Drosophila melanogaster into 4 groups according to LAS concentrations: a low dose group with LAS 150 mg/kg, a middle dose group with LAS 300 mg/kg,a high dose group with LAS 600 mg/kg, and a control group without LAS, respectively. The changes of the reproductive capacity, median lethal time, mean life-span and max mean life-span of drosophila melanogaster with different doses of LAS were measured and compared with those of the control.The pupa numbers of filial generation of Drosophila melanogaster in the low, middle, and high dose groups (85.07%, 84.59% and 71.88%, respectively) were lower than those in the control group (P0.01). The median lethal time, mean life-span and max mean life-span of Drosophila melanogaster in the low, middle, and high dose groups were shorter than those in the control group (P0.05). The change of life-span of Drosophila melanogaster in the high dose group was remarkable: the median lethal time of female and male shortened 13 days and 15 days, the mean life-span of female and male shortened 18 days and 14 days, and the max mean life-span of female and male shortened 14 days and 12 days, respectively.LAS has definite toxicity to Drosophila melanogaster, which can degrade the reproductive capacity of Drosophila melanogaster and shorten the life-span of Drosophila melanogaster.