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Organic electrochemical transistors (OECTs) and OECT-based circuitry offer great potential in bioelectronics, wearable electronics and artificial neuromorphic electronics because of their exceptionally low driving voltages (10 mS) and biocompatibility1–5. However, the successful realization of critical complementary logic OECTs is currently limited by temporal and/or operational instability, slow redox processes and/or switching, incompatibility with high-density monolithic integration and inferior n-type OECT performance6–8. Here we demonstrate p- and n-type vertical OECTs with balanced and ultra-high performance by blending redox-active semiconducting polymers with a redox-inactive photocurable and/or photopatternable polymer to form an ion-permeable semiconducting channel, implemented in a simple, scalable vertical architecture that has a dense, impermeable top contact. Footprint current densities exceeding 1 kA cm−2 at less than ±0.7 V, transconductances of 0.2–0.4 S, short transient times of less than 1 ms and ultra-stable switching (>50,000 cycles) are achieved in, to our knowledge, the first vertically stacked complementary vertical OECT logic circuits. This architecture opens many possibilities for fundamental studies of organic semiconductor redox chemistry and physics in nanoscopically confined spaces, without macroscopic electrolyte contact, as well as wearable and implantable device applications.

Water-enabled electricity generation (WEG) technologies are considered to be an attractive and renewable approach to meet energy crisis and environmental pollution globally. However, the existing WEG technologies still face tremendous challenges including high material cost, harmful components, and specific environmental requirements. Herein, a high-performance wood-based moisture-enabled electric generator (WMEG) is fabricated. Natural wood is cut perpendicular to the tree growth direction and engineered by simple chemical modification. The obtained bilayer wood membrane has robust mechanical framework with aligned ion nanochannels, abundant dissociated functional groups, and spontaneous water adsorption in the air. At the relative humidity of 85%, one WMEG can generate a voltage of 0.57 V. The device can also effectively sense biological water information as a self-powered sensor. The biophile design contributes a practical moist-electric generation strategy that offers clean energy, especially for undeveloped and disaster-relief regions where electricity is limited by high cost or crippled power facilities.

Although bone is a self-healing organ and is able to repair and restore most fractures, large bone fractures, about 10%, are not repairable. Bone grafting, as a gold standard, and bone tissue engineering using biomaterials, growth factors, and stem cells have been developed to restore large bone defects. Since bone regeneration is a complex and multiple-step process and the majority of the human genome, about 98%, is composed of the non-protein-coding regions, non-coding RNAs (ncRNAs) play essential roles in bone regeneration. Recent studies demonstrated that long ncRNAs (lncRNAs) and circular RNAs (circRNAs), as members of ncRNAs, are widely involved in bone regeneration by interaction with microRNAs (miRNAs) and constructing a lncRNA or circRNA/miRNA/mRNA regulatory network. The constructed network regulates the differentiation of stem cells into osteoblasts and their commitment to osteogenesis. This review will present the structure and biogenesis of lncRNAs and circRNAs, the mechanism of bone repair, and the bone tissue engineering in bone defects. Finally, we will discuss the role of lncRNAs and circRNAs in osteogenesis and bone fracture healing through constructing various lncRNA or circRNA/miRNA/mRNA networks and the involved pathways.

Water-induced electricity generators (WIEGs) based on solid-water interactions are considered as promising next-generation power sources due to the abundance and sustainability of water. Nevertheless, the contributions of electrochemistry and solid surface chemistry to the electricity generation of WIEGs have not gained enough attention. Here, a series of WIEGs is designed to investigate the effects of different pairings of electrically conductive solids, device configurations, solid surface chemistry, and electrolytes in water on the electricity generation. It is revealed that the electricity generated from these devices is mainly ascribed to the electrochemical reactions involved by the conductive solids, dissolved oxygen, and liquid water that convert chemical energy into electricity. The dissociation of surface functional groups also affects the generated voltage in different electrolytes. The output performance can be enhanced by using more active solids and salty/acidic electrolytes. Finally, a semi-solid-state portable WIEG capable of producing stable voltage for at least 30 days was constructed, demonstrating great potential for driving portable/wearable/flexible electronics and internet of things devices.

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.

Wearable pressure sensors have gained widespread popularity. However, they fail to meet the demand of multi-scenarios applications and large-scale fabrication. Herein, we report a flexible, fully integrated, and wireless pressure sensing chip system by integrating a sensitivity-tunable sensor with a flexible printed circuit board on polyimide films. The sensor incorporates laser-induced graphene-based interdigitated electrode with a conductive sponge fabricated by in situ growth of silver nanoparticles (AgNPs) on a MXene-coated sponge. The sensitivity can be tuned by changing the growth density of AgNPs, with a higher density of AgNPs corresponding to higher sensitivity. The highest sensitivity can reach 0.90 kPa−1, which is higher than the sensor without AgNPs (0.10 kPa−1). This system is expected to find applications in multi-scenarios, such as fruit growth and pulse signal. All these studies indicate that this integrated sensing chip system possesses the potential in improving the fabrication efficiency and sensing convenience for future wearable electronics.

HighlightsA portable system based on real-time fluorescence analysis was developed for field detection of Candidatus Liberibacter asiaticus within 40 min from sample to answer.A smartphone-assisted device was designed for easy operation, reliable nucleic acid amplification, and highly sensitive fluorescence detection, with sensitivity comparable to that of a commercial instrument.A novel homemade 3D printed box was used for in-field reagent storage, and it could maintain low temperature (This fully integrated system is stable, easy to use, inexpensive, and has great application prospects in resource-limited areas.Abstract. Candidatus Liberibacter asiaticus (Las) is a main causal agent of huanglongbing (HLB), a destructive disease that has greatly reduced citrus yields and quality. Instruments with high sensitivity and portability are urgently required for on-site testing. In this study, a novel sample-to-answer optical system for on-site detection of Las was developed. Three major functions, including DNA extraction, amplification, and detection, are integrated into a portable case. This system mainly consists of (1) a specially designed 3D printed box for on-site reagent storage that can maintain low temperature (below 4°C) for 7.5 h at ambient temperature (35°C); (2) a custom device, called the IF-Device, for DNA amplification and detection of HLB, with an optimized optical structure, a sensitive signal processing circuit, and a precise temperature control algorithm with an accuracy of ±0.1°C; and (3) a battery-based power supply for the whole system. In a typical test using sodium fluorescein as a standard model, the results showed that the sensitivity of this system (1.0 nM) could easily meet the requirements of fluorescence biosensors. The feasibility of this homemade system was evaluated with samples extracted from infected citrus leaves based on the loop-mediated isothermal amplification (LAMP) method, and the limit of detection (LOD) was approximately 1.0 × 10-4 ng µL-1. The whole detection process for eight samples could be simultaneously accomplished within 40 min, and the results could be displayed on a smartphone in real-time. Moreover, the portable case is anti-interference, low cost, and only 2 kg in weight. Considering its sensitivity, stability, and portability, this highly integrated system possesses promising prospects for in-field detection. Keywords: Field detection, Fluorescence biosensor, Huanglongbing, Isothermal amplification, Sample-to-answer.

The ectopic co-expression of taste and olfactory receptors in cardiomyocytes provides not only possibilities for the construction of biomimetic gustatory and olfactory sensors but also promising novel therapeutic targets for tachycardia treatment. Here, bitter taste and olfactory receptors endogenously expressed in HL-1 cells were verified by RT-PCR and immunofluorescence staining. Then HL-1 cardiomyocyte-based integrated gustatory and olfactory sensing array coupling with the microelectrode array (MEA) was first constructed for drugs screening and evaluation for tachycardia treatment. The MEA sensor detected the extracellular field potentials and reflected the systolic-diastolic properties of cardiomyocytes in real time in a label-free and non-invasive way. The in vitro tachycardia model was constructed using isoproterenol as the stimulator. The proposed sensing array facilitated potential drug screening for tachycardia treatment, such as salicin, artemisinin, xanthotoxin, and azelaic acid which all activated specific receptors on HL-1 cells. IC

Plants have complex internal signaling pathways to quickly adjust to environmental changes and harvest energy from the environment. Facing the growing population, there is an urgent need for plant transformation and precise monitoring of plant growth to improve crop yields. Nanotechnology, an interdisciplinary research field, has recently been boosting plant yields and meeting global energy needs. In this context, a new field, “plant nanoscience,” which describes the interaction between plants and nanotechnology, emerges as the times require. Nanosensors, nanofertilizers, nanopesticides, and nano‐plant genetic engineering are of great help in increasing crop yields. Nanogenerators are helping to develop the potential of plants in the field of energy harvesting. Furthermore, the uptake and internalization of nanomaterials in plants and the possible effects are also worthy of attention. In this review, a forward‐looking perspective on the plant nanoscience is presented and feasible solutions for future food shortages and energy crises are provided., This review provides the first detailed introduction of plant nanoscience, including nanosensors, nanofertilizers, nanopesticides, nanomaterials‐mediated gene transformation, nanogenerators, and nanotoxicology. The interaction between nanomaterials and plants, as well as, the advanced application fields of nanotechnology in plants are discussed deeply to better manage the growth of plants and offer guidance for the future research and practical applications.

With the rapid worldwide industrial development, large amounts of pollutants such as heavy metals are discharged into the water sources, causing a huge threat to living beings. To mitigate this issue, there is an urgent need for new water treatment strategies. Inspired by a natural shell nacre structure and a multidimensional hybrid concept, we demonstrate multilayered inorganic-organic hybrid membranes using metallic molybdenum disulfide (MoS2) as two-dimensional transition metal dichalcogenide nanosheets and one-dimensional silk nanofibrils for water purification. Because of its possessing negatively charged layers and interaction sites, the hybrid film could adsorb metal ions and dyes from water. The separation performance can be tuned by changing the component ratios of these two nanomaterials. During filtration, due to the reducing effect of the MoS2 nanosheets, precious metal ions are reduced to their nanoparticle form without any further thermal or chemical treatments. In addition to the one-step removal and recovery of metal ions, the hybrid membranes exhibit excellent potential for the determination and removal of different dyes from water. The results of this research can open up an effective and green avenue for water purification and recovery of metal ions dissolved in water.

Recent advances in biomaterial designing techniques offer immense support to tailor biomimetic scaffolds and to engineer the microstructure of biomaterials for triggering bone regeneration in challenging bone defects. The current review presents the different categories of recently explored strontium-integrated biomaterials, including calcium silicate, calcium phosphate, bioglasses and polymer-based synthetic implants along with their in vivo bone formation efficacies and/or in vitro cell responses. The role and significance of controlled drug release scaffold/carrier design in strontium-triggered osteogenesis was also comprehensively described. Furthermore, the effects of stem cells and growth factors on bone remodeling are also elucidated.

Highly conductive fibers play an essential role in the development of electronic textiles for wearable devices. Even though great progress has been made recently, big challenges of developing simple and rapid methods to prepare functional fibers with stretchability, high sustainability, and electrical conductivity still remain. Herein, we proposed a simple, rapid, and scalable approach to fabricate stretchable and conductive fibers by growing Au nanostructures on a double-twisted fiber coated with metallic MoS2 nanosheets. The formation of Au nanostructures with a unique "popcorn"-like shape (namely, Au "nanopopcorn", AuNPC) occurs instantaneously and spontaneously on the surface of MoS2-coated fiber, without any additional reducing reagents or heating conditions. Moreover, the overall fabrication process takes less than 5 min, demonstrating the realization of fast fabrication of functional conductive fibers. The obtained fiber with piezoresistive property can be fabricated into a pressure sensor. The unique morphology of AuNPC with a rough surface can significantly enhance the performance of the pressure sensor, with high sensitivity of up to 0.19 kPa-1 and a fast response time of 93 ms. Furthermore, the functional fiber can be woven into electronic textiles with sensing arrays, which has multiple two-dimensional (2D) force mapping properties. Therefore, we envision that this simple, rapid, and scalable method to fabricate conductive functional fibers would show great potential in the field of electronic textiles and wearable devices.

Nucleic acid-based techniques could achieve highly sensitive detection by amplifying template molecules to millions of folds. It has been one of the most valued analytical methods and is applied in many detection fields, such as diagnosis of infectious diseases, food safety assurance and so on. Nucleic acid-based techniques consist of three steps: nucleic acid extraction, amplification, and product detection. Among them, the detection step plays a vital role because it shows the results directly. As the trend of detection is simple, rapid and instrument-free, it is of necessity to carry out visual detection, where the result read-out could be visible and distinguished by the naked eye. In this critical review, advanced visual detection methods are summarized and discussed in detail, aiming to promote the potential application in on-site detection.

Nanofluidic channels based on 2D nanomaterials are promising to harvest osmotic energy for their high ion selectivity and osmotic conductivity. However, anion-selective nanofluidic channels are rare and chemical modification is necessary through fabrication. Here, a naturally anion-selective composite membrane is reported, that is, NiAl-Layered double hydroxide (LDH) coated anodic aluminum oxide (LDH@AAO), using a simple precipitant-free in situ growth technique. Positively charged LDH plates growing in channels of AAO function as screening layers for anions. Both experiments and theoretical simulations are enforced to certify the vital role of LDH growth in ion distribution and salinity gradient energy conversion. The composite membrane achieves high output performance and long-term stability. Furthermore, novel applications of nanofluidic channels are explored in hydroponic production and design a real-time detecting system based on LDH@AAO composite membranes for nutrient solution. This work provides insights into naturally anion-selective nanofluidic channels for osmotic energy harvesting and broadens the application in agricultural information sensing.

Electrolyte-gated transistors (EGTs) hold great promise for next-generation printed logic circuitry, biocompatible integrated sensors, and neuromorphic devices. However, EGT-based complementary circuits with high voltage gain and ultralow driving voltage (110) under a supply voltage of only 0.7 V. Furthermore, NAND and NOR logic circuits on both rigid and flexible substrates are realized, enabling not only excellent logic response with driving voltages as low as 0.2 V but also impressive mechanical flexibility down to 1-mm bending radii. Finally, the HCIN was applied in electrooculographic (EOG) signal monitoring for recording eye movement, which is critical for the development of wearable medical sensors and also interfaces for human–computer interaction; the high voltage amplification of the present HCIN enables EOG signal amplification and monitoring in which a small ∼1.5 mV signal is amplified to ∼30 mV.

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

The development and application of cell-based biosensors (CBBs) provides a convenient strategy for rapid detection of target analytes. The CBBs had been widely applied in the fields of food safety, environment monitoring, and medicine diagnosis due to their advantages of short response time, easy operation, low toxicity, and portability. However, the CBBs based on two-dimensional (2D) cultured cells in-vitro suffer from a lower cell viability and isolated physiology, which had blocked the accurate evaluations of these biosensors. With the development of nanotechnology and three-dimensional (3D) printing technology, cells fixed in a 3D biosensor or a 3D microenvironment have shown great improvement in the sensitivity and detection authenticity than conventional CBBs. To promote the further development of CBBs, in this paper, we reviewed the related technologies used to construct 3D bionic cell chips including organic/inorganic agents and operating approaches suitable for constructing 3D cell cultural microenvironment. Then, the applications of 3D bionic cell chip based on microbial and mammalian cell biosensors in food safety field were discussed during recent ten years. Finally, the current challenges and further directions were summarized and prospected.

Digital nucleic acid amplification techniques are powerful and attractive approaches for providing sensitive and absolute quantification in biology. Among these, digital loop-mediated isothermal amplification (dLAMP) shows the potential for field detection, since its robustness and independence from thermal cycling. The key of dLAMP is to generate a large number of individual droplets or microwells. However, an auxiliary precision pump is always required for sample digitalization. In addition, current systems for droplet dLAMP usually need to transfer the droplets after digitalization or amplification. Herein, we developed and evaluated a pump-free microfluidic chip for duplex droplet dLAMP (TriD-LAMP) detection. This chip was designed based on step emulsification and contains a droplet generation zone and a droplet storage zone. Droplets are formed through the step due to the difference in Laplace pressure. There are 64 parallel nozzles that could generate tens of thousands of uniform droplets manually (variation5%). The storage zone for droplets collection was previously filled with oil containing fluorosurfactant that keeps the droplets from fusing and evaporation during the amplification. Therefore, this custom chip is able to perform all stages of the dLAMP process without transferring droplets. Combined with the optimized fluorescent probe method, the chip achieves accurate quantification of the E. coli DNA down to 19.8 copies/μL. As a proof of concept, the simultaneous quantification of two targets was successfully realized on this custom chip. Conclusively, this integrated, pump-free TriD-LAMP chip can provide a promising tool for multiple targets detection in clinical diagnostics and point-of-care applications.

Emerging photocatalytic technology promises to provide an effective solution to the global energy crisis and environmental pollution. Graphite carbon nitride (g-C

Detecting volatile organic compounds (VOCs) in human breath is critical for the early diagnosis of diseases. Good selectivity of VOC sensors is crucial for the accurate analysis of VOC biomarkers in human breath, which consists of more than 200 types of VOCs. In this paper, a flexible virtual sensor array (FVSA) was proposed based on a sensing layer of MXene and laser-induced graphene interdigital electrodes (LIG-IDEs) for detecting VOCs in exhaled human breath. The fabrication of LIG-IDEs avoids the costly and complicated procedures required for the preparation of traditional IDEs. The FVSA's responses of multiple parameters help build a unique fingerprint for each VOC, without a need for changing the temperature of the sensing element, which is commonly used in the VSA of semiconductor VOC sensors. Based on machine learning algorithms, we have achieved highly precise recognition of different VOCs and mixtures and accurate prediction (accuracy of 89.1%) of the objective VOC's concentration in variable backgrounds using this proposed FVSA. Moreover, a blind analysis validates the capacity of the FVSA to identify alcohol content in human breath with an accuracy of 88.9% using breath samples from volunteers before and after alcohol consumption. These results show that the proposed FVSA is promising for the detection of VOC biomarkers in human exhaled breath and early diagnosis of diseases.

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.

Bone is a self-regenerative tissue that can repair small defects and fractures. In large defects, bone tissue is unable to provide nutrients and oxygen for repair, and autologous grafting is used as the gold standard. As an alternative method, the bone tissue regeneration approach uses osteoconductive biomaterials to overcome bone graft disadvantages. However, biomaterials are considered as foreign components that can stimulate host immune responses. Although traditional principles have been aimed to minimize immune reactions, the design of biomaterials has steadily shifted toward creating an immunomodulatory microenvironment to harness immune cells and responses to repair damaged tissue. Among immune cells, macrophages secrete various immunomodulatory mediators and crosstalk with bone-forming cells and play key roles in bone tissue engineering. Macrophage polarization toward M1 and M2 subtypes mediate pro-inflammatory and anti-inflammatory responses, respectively, which are crucial for bone repairing at different stages. This review provides an overview of the crosstalk between various immune cells and biomaterials, macrophage polarization, and the effect of physicochemical properties of biomaterials on the immune responses, especially macrophages, in bone tissue engineering.

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.

Two−dimensional transition−metal dichalcogenide (TMD) nanosheets have been regarded as a class of promising nanomaterials in various applications due to their outstanding optical, electronic, and catalytic properties. Here, we explored the metal ion-induced optical behavior of four typical TMD nanosheets (WS2, MoS2, WSe2, and MoSe2) prepared via a kitchen blender-assisted shear exfoliation method. Results show that upon the addition of certain amount of metal ions, layered 2H phase TMD nanosheets would aggregate rapidly, resulting in their growth in both planar size and thickness, which leads to the change of their characteristic absorption peak position. Inspired by this phenomenon, a sensitive and label-free colorimetric sensing strategy for DNA detection was develop combined with the discriminative affinity of TMD nanosheets towards single−strand DNA and double−strand DNA. Furthermore, hybridization chain reaction is introduced to achieve higher sensitivity towards DNA detection. We anticipate that this proposed colorimetric sensor would significantly expand the scope of 2D TMD nanosheets and hold great application prospects in DNA sensing strategies in various fields.

Heavy metal ions, one of the most important pollutants today, widely exist in the environment, and can cause different degrees of damage to the ecological environment and human body. In the face of the increasingly severe situation of heavy metal pollution, it is urgent to develop a rapid, robust, sensitive, and convenient method for heavy metal ions detection. Compared with the traditional detection methods, the screen-printed electrochemical sensor based on nanomaterials has the advantages of rapid detection speed, high sensitivity, high selectivity, and high stability, which make it become the preferred method for the detection of heavy metal ions. This review presents the recent progress in the field of heavy metal ions determination using various nanomaterials-enabled screen-printed electrochemical sensors. The fabrication strategy and analytical performance of carbon nanomaterials (such as carbon nanotubes and graphene), metal nanomaterials (such as gold nanoparticles and silver nanoparticles), and metal oxide nanomaterials (such as Fe3O4 nanoparticles and Bi2O3 nanoparticles)-enabled disposable sensors for electrochemical determination of heavy metal ions are summarized systematically. In addition, the application of these sensors in real samples for the analysis of heavy metal ions is discussed in detail, and the future development in this field is also provided.

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.

Currently, food allergy is a worldwide public health problem, of which peanut allergy is more severe. Peanut allergy is usually lifelong and even trace amount of peanut allergens can cause severe anaphylactic reactions. Nowadays there is no complete cure for sensitized individuals. The dominant prevention is to avoid exposure to peanuts and peanut products. But there are risks of false ingredient labeling and cross-contamination during food processing. Hence, it is important and urgent to detect peanut allergens in food products. This review highlights advances and future trends in DNA-based methods applied to detect peanut allergens in processed food. A summary of published methods for detecting peanut allergens in food is given with a comparison of DNA targets and limit of detection.