Portable self-powered electrochemical aptasensor for ultrasensitive and real-time detection of microcystin-RR based on hydrovoltaic-photothermal coupling effect.

Coupling different energy harvesting technologies to obtain an excellent output signal is essential for the development of high-performance self-powered electrochemical sensors. Herein, a novel hydrovoltaic-photothermal coupling self-powered electrochemical aptasensing platform was designed for sensitive detection of microcystin (MC-RR) with a digital multimeter as a direct visual readout strategy. The straightforward ultrasonic method was employed to synthesize polyaniline (PANI) and bismuth oxybromide (BiOBr) nanosheets, which were then integrated as active components in a hydrovoltaic device. The unique layer structure of two-dimensional (2D) nanomaterials BiOBr can create flexible interlayer spaces to accommodate various ions and water molecules, which was beneficial to construct evaporation-driven channels. Meanwhile, the exceptional photothermal characteristics of polyaniline could accelerate the water evaporation rate, consequently boosting the migration speed of charge carriers and increasing output signal. Moreover, a digital multimeter was connected to the constructed sensor for real-time displaying the output signal. With the assistance of aptamer, a novel self-powered electrochemical aptasensing platform was constructed for sensitive detection of MC-RR. Under optimum conditions, the output signal of the hydrovoltaic-photothermal coupling cell was linearly related to the logarithm of MC-RR concentration in the range of 1 fM to 1 nM with a detection limit of 0.31 fM (S/N = 3). Furthermore, this sensor also exhibited many advantages such as high selectivity, good repeatability and portability. Such novel strategy not only offers a completely new general approach to construct high-performance self-powered devices for the detection of MC-RR, but also provides a new strategy for advancing the miniaturization and field application of self-powered electrochemical sensors.

Role of Piezoelectricity in Disease Diagnosis and Treatment: A Review.

Because of their unique electromechanical coupling response, piezoelectric smart biomaterials demonstrated distinctive capability toward effective, efficient, and quick diagnosis and treatment of a wide range of diseases. Such materials have potentiality to be utilized as wireless therapeutic methods with ultrasonic stimulation, which can be used as self-powered biomedical devices. An emerging advancement in the realm of personalized healthcare involves the utilization of piezoelectric biosensors for a range of therapeutic diagnosis such as diverse physiological signals in the human body, viruses, pathogens, and diseases like neurodegenerative ones, cancer, etc. The combination of piezoelectric nanoparticles with ultrasound has been established as a promising approach in sonodynamic therapy and piezocatalytic therapeutics and provides appealing alternatives for noninvasive treatments for cancer, chronic wounds, neurological diseases, etc. Innovations in implantable medical devices (IMDs), such as implantable piezoelectric energy generator (iPEG), offer significant advantages in improving physiological functioning and ability to power a cardiac pacemaker and restore the heart function. This comprehensive review critically evaluates the role of piezoelectricity in disease diagnosis and treatment, highlighting the implication of piezoelectric smart biomaterials for biomedical devices. It also discusses the potential of piezoelectric materials in healthcare monitoring, tissue engineering, and other medical applications while emphasizing future trends and challenges in the field.

Comprehensive Insights on MXene-Based TENGs: from Structures, Functions to Applications.

The rapid advancement of triboelectric nanogenerators (TENGs) has introduced a transformative approach to energy harvesting and self-powered sensing in recent years. Nonetheless, the untapped potential of TENGs in practical scenarios necessitates multiple strategies like material selections and structure designs to enhance their output performance. Given the various superior properties, MXenes, a kind of novel 2D materials, have demonstrated great promise in enhancing TENG functionality. Here, this review comprehensively delineates the advantages of incorporating MXenes into TENGs, majoring in six pivotal aspects. First, an overview of TENGs is provided, stating their theoretical foundations, working modes, material considerations, and prevailing challenges. Additionally, the structural characteristics, fabrication methodologies, and family of MXenes, charting their developmental trajectory are highlighted. The selection of MXenes as various functional layers (negative and positive triboelectric layer, electrode layer) while designing TENGs is briefed. Furthermore, the distinctive advantages of MXene-based TENGs and their applications are emphasized. Last, the existing challenges are highlighted, and the future developing directions of MXene-based TENGs are forecasted.

Reversibly Compressible Silanated Cellulose Nanofibril Aerogel for Triboelectric Taekwondo Scoring Sensors.

The integration of bio-based materials into triboelectric nanogenerators (TENGs) for energy harvesting from human body motions has sparked considerable research attention. Here, a silanated cellulose nanofibril (SCNF) aerogel is reported for structurally reliable TENGs and reversely compressible Taekwondo scoring sensors under repeated impacts. The preparation of the aerogel involves silanizing cellulose nanofibers (CNFs) with vinyltrimethoxysilane (VTMS), following by freeze-drying and post-heating treatment. The SCNF aerogel with crosslinked physico-chemical bonding and highly porous network is found to exhibit superior mechanical strength and reversible compressibility as well as enhanced water repellency and electron-donating ability. The TENG having a tribo-positive SCNF layer exhibits exceptional triboelectric performances, generating a voltage of 270 V, current of 11 µA, and power density of 401.1 mW m-2 under an applied force of 8 N at a frequency of 5 Hz. With its inherent merits in material composition, structural configuration, and device sensitivity, the SCNF TENG demonstrates the capability to seamlessly integrate into a Taekwondo protection gear, serving as an efficient self-powered sensor for monitoring hitting scores. This study highlights the significant potential of a facilely fabricated SCNF aerogel for the development of high-performance, bio-friendly, and cost-effective Bio-TENGs, enabling their application as self-powered wearable devices and sports engineering sensors.

Rational Design of Triboelectric Materials and Devices for Self-Powered Food Sensing.

Against the backdrop of rapid advancements in 5G and Internet of Things (IoT) technologies, there is an urgent need to upgrade food sensing systems to achieve automation, digitalization, and intelligence. However, this transformation process faces numerous challenges. Triboelectric nanogenerators (TENGs), as an emerging energy conversion and sensing technology, play a crucial role in this context. They not only provide power to functional devices but also serve as sensors in multifunctional self-powered food sensing systems, capable of detecting various physical and chemical information. This review explores the development of TENGs in the field of food sensing, focusing on the working principles of their self-powered sensing. The review also systematically organizes and classifies the material and device designs used for TENGs in various food applications. Based on the performance of TENGs, a detailed introduction is provided on the specific applications of self-powered food sterilization, self-powered food quality monitoring, and self-powered taste sensing in the field of food safety. Finally, this paper discusses the challenges and corresponding strategies of TENGs in the food sensing field. The aim is to further promote unmanned and smart services and management in the food sector and to provide new research perspectives.

Performance Enhancement of Self-Powered Electrochromic Device via a PEDOT:PSS Electrode Inherited with Intrinsic Roughness of Substrate.

The electrode optimization and rational design are of great significance for the performance enhancement of self-powered electrochromic devices (ECDs). It can be effectively enhanced by developing interfacial properties of electrodes, which can promote the internal ion transport within functional components consisting of an electrode, electrochromic layer, and electrolyte layer and thus obtain performance improvement of fabricated devices. This work aims to construct the electrode of poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS) on different substrates and promote interface performance of the prepared electrodes via inheriting the surface topography of substrates. Besides, the prepared PEDOT:PSS electrodes as a dual-function layer including the electrochromic and electrode layer are employed to assemble the ECDs. It is found that the intrinsic roughness of the paper substrate can facilitate the electrochemical performance of the prepared PEDOT:PSS electrode on it effectively, thereby showing a superior electrochemical surface area and diffusion coefficient as well as a lower charge-transfer resistance of 13.56 Ω. Similarly, for the prepared self-powered ECD on the paper substrate, it also indicates a high light absorption property (0.413), well-defined electrochromic contrast (33.09), fast switching (τc = 4.0 s, τb = 6.8 s), high coloration efficiency (92.275 cm2 C-1), high areal capacity (10.93 mAh m-2) at 0.01 mA cm-2, and lower equivalent series resistance (176.2 Ω) in comparison to parallel ECDs on the PET and glass substrate. Leveraging the intrinsic roughness of the substrate is able to enhance the electrochemical performance of electrodes, which can also provide a new strategy for the construction of high-performance self-powered ECDs.

Enhancement of photovoltaic parameters of thermally stable graphene/LaVO3semitransparent solar cell by employing interfacial graphene quantum dots.

Semitransparent solar cells are attracting attention not only for their visual effects but also for their ability to effectively utilize solar energy. Here, we demonstrate a translucent solar cell composed of bis(trifluoromethane sulfonyl)-amide (TFSA)-doped graphene (Gr), graphene quantum dots (GQDs), and LaVO3. By introducing a GQDs intermediate layer at the TFSA-Gr/LaVO3interface, we can improve efficiency by preventing carrier recombination and promoting charge collection/separation in the device. As a result, the efficiency of the GQDs-based solar cell was 4.35%, which was higher than the 3.52% of the device without GQDs. Furthermore, the average visible transmittance of the device is 28%, making it suitable for translucent solar cells. The Al reflective mirror-based system improved the power conversion efficiency by approximately 7% compared to a device without a mirror. Additionally, the thermal stability of the device remains at 90% even after 2000 h under an environment with a temperature of 60 °C and 40% relative humidity. These results suggest that TFSA-Gr/GQDs/LaVO3-based cells have a high potential for practical use as a next-generation translucent solar energy power source.

Advances in Graphene-Based Electrode for Triboelectric Nanogenerator.

With the continuous development of wearable electronics, wireless sensor networks and other micro-electronic devices, there is an increasingly urgent need for miniature, flexible and efficient nanopower generation technology. Triboelectric nanogenerator (TENG) technology can convert small mechanical energy into electricity, which is expected to address this problem. As the core component of TENG, the choice of electrode materials significantly affects its performance. Traditional metal electrode materials often suffer from problems such as durability, which limits the further application of TENG. Graphene, as a novel electrode material, shows excellent prospects for application in TENG owing to its unique structure and excellent electrical properties. This review systematically summarizes the recent research progress and application prospects of TENGs based on graphene electrodes. Various precision processing methods of graphene electrodes are introduced, and the applications of graphene electrode-based TENGs in various scenarios as well as the enhancement of graphene electrodes for TENG performance are discussed. In addition, the future development of graphene electrode-based TENGs is also prospectively discussed, aiming to promote the continuous advancement of graphene electrode-based TENGs.

Tactile Sensing and Rendering Patch with Dynamic and Static Sensing and Haptic Feedback for Immersive Communication.

Wearable human-machine interface (HMI) with bidirectional and multimodal tactile information exchange is of paramount importance in teleoperation by providing more intuitive data interpretation and delivery of tactilely related signals. However, the current sensing and feedback devices still lack enough integration and modalities. Here, we present a Tactile Sensing and Rendering Patch (TSRP) that is made of a customized expandable array which consists of a piezoelectric sensing and feedback unit fused with an elastomeric triboelectric multidimensional sensor and its inner pneumatic feedback structure. The primary functional unit of TSRP is mainly featured with a soft silicone substrate with compact multilayer structure integrating static and dynamic multidimensional tactile sensing capabilities, which synergistically leverage both triboelectric and piezoelectric effects. Additionally, based on the air chamber created by the triboelectric sensor and the converse piezoelectric effect, it provides pneumatic and vibrational haptic feedback simultaneously for both static and dynamic perception regeneration. With the aid of the other variants of this unit, the array shaped TSRP is capable of simulating different terrains, geometries, sliding, collisions, and other critical interactive events during teleoperation via skin perception. Moreover, immediate manipulation can be done on TSRP through the tactile sensors. The preliminary demonstration of TSRP interface with a completed control module in robotic teleoperation is provided, which shows the feasibility of assisting certain tasks in a complex environment by direct tactile communication. The proposed device offers a potential method of enabling bidirectional tactile communication with enriched key information for improving interaction efficiency in the fields of robot teleoperation and training.

Laser-induced CdS/TiO2/graphene dual photoanodes for ratiometric self-powered photoelectrochemical sensor: an innovative approach for aflatoxin B1 detection.

A ratiometric self-powered photoelectrochemical sensor based on laser direct writing technology was constructed to address the problem that the conventional single-signal detection mode was susceptible to the influence of instrumentation and environmental factors, which interfered with the detection results. Laser-induced CdS/TiO2/Graphene was prepared as dual photoanodes (PA1 and PA2), which were controlled by multiplexed switches to form a photocatalytic fuel cell with Pt cathode. By modifying the aptamer of aflatoxin B1 (AFB1) on the photoanode surface, the target was specifically captured to the electrode surface to form a biological complex, which increased the steric hindrance and affected the electron transfer, thus reducing the output signal of the sensor. Targets with different concentrations were incubated on the surface of PA1, and targets with fixed concentrations were incubated on the surface of PA2. Under the control of the multiplex switch, the output signals of the two photoanodes were recorded, and the ratio of these two signals was used as the basis for the quantitative detection of AFB1. The sensor output was linearly increasing with the logarithm of AFB1 concentration from 1.0 to 150 ng mL-1 and the detection limit was 0.0974 ng mL-1. Additionally, this method had good stability, fast response, and good selectivity to real samples, providing an effective method for food safety monitoring.

Enhanced Responsivity and Photostability of Cs3Bi2I9-Based Self-Powered Photodetector via Chemical Vapor Deposition Engineering.

Lead-based halide perovskites have gained significant prominence in recent years in optoelectronics and photovoltaics, owing to their exceptional optoelectronic properties. Nonetheless, the toxicity of lead (Pb) and the stability concern pose obstacles to their potential for future large-scale market development. Herein, stable lead-free Cs3Bi2I9 (CBI) films are presented with smooth and compact morphologies synthesized via chemical vapor deposition (CVD), demonstrating their application as an UV photodetector in a self-powered way. The self-powered photodetectors (SPDs) exhibit remarkable characteristics, including a responsivity of 1.57 A W-1 and an impressive specific detectivity of 3.38 × 1013 Jones under the illumination of 365 nm at zero bias. Furthermore, the SPDs exhibit a nominal decline (≈2.2%) in the photocurrent under constant illumination over 500 h, highlighting its impressive long-term operational stability. Finally, the real-time UV-detection capability of the device is demonstrated by measuring the photocurrent under various conditions, including room light and sunlight at different times. These findings offer a new platform for synthesizing stable and high-quality perovskite films, and SPDs for advancing the development of wearable and portable electronics.

Efficiently Fabricated Core-Sheath Piezoelectric Sensor Based on PVDF Microfibrillar Bundle.

With the rapid development of information technology (e.g., Internet of Things (IoT) and artificial intelligence (AI)), piezoelectric sensor (i.e., piezoelectric nanogenerator, PENG) receives an increasing number attention in the field of self-powered wearable devices. Taking piezoelectric fiber as an example, it shows promising application for wearable devices owing to its light weight and high flexibility compared with block electronic devices. However, it still remains a challenge to fabricate low-cost and high-performance piezoelectric fiber via a large-scale but efficient method. In this study, via extrusion molding and leaching, a core-sheath piezoelectric sensor is facilely fabricated, whose core and sheath layer are respectively slender steel wire (i.e., electrode) and PVDF microfibrillar bundle (PMB) (i.e., piezoelectric layer). Such piezoelectric sensor shows decent output performance in both pressing (12.3 V) and bending (0.32 V) mode. Meanwhile, it possesses sensitive stress responsiveness when serving for self-powered sensing. Furthermore, such piezoelectric sensors can realize wearable signal transmission and human motion monitoring, showing promising potential for wearable devices in the future. This work proposes a large-scale but efficient method for fabricating high-performance PVDF microfibril based piezoelectric fiber, opening a new pathway to develop self-powered sensors following the concept of polymer "structuring" processing.

A Highly Robust, Multifunctional, and Breathable Bicomponent Fibers Thermoelectric Fabric for Dual-Mode Sensing.

Wearable thermoelectric (TE) materials are seen as excellent candidates for flexible electronics because of their unique self-powered properties, multistimulus sensing and human waste heat conversion. However, currently reported flexible TE materials still face challenges such as poor durability, uncomfortable wearing and sensing signals crosstalking each other. Herein, this study describes a hot-air cross-linking method for the preparation of multifunctional TE fabrics with enhanced durability. Poly(ethylene terephthalate) (PET) fibers with core and sheath structures having different melting points were selected as flexible substrates. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) and single-walled carbon nanotubes (SWCNTs) were embedded stably on the surface of the sheath layer in the presence of heat treatment. The fiber-welded structure created by thermal cross-linking improves the durability of TE fabrics, including consistent mechanical and electrical properties after a 6 h wash test and 6000 compression cycles. The unique fiber structure of TE fabrics ensures excellent breathability (313.7 mm s-1 at 200 Pa), which meets the breathability requirements for human wear. In addition, the fiber-prepared sensors have excellent compressive strain response (20 ms response time and 30 ms recovery time) and precise temperature discrimination (0.17 K minimum discrimination temperature) for accurate real-time monitoring of the sensed signals. Thus, the TE fabrics can be used for human motion recognition, including pulse monitoring, sign language expression, and motions in joint areas. Moreover, the fabricated wearable TE device is connected to a Bluetooth module for wireless transmission, which can be used for mechanical and temperature sensing of the robot arm without signals crosstalking. This new durable TE fabric paves the way for the next generation of smart wearable technology.

Tough and temperature-tolerance cellulose/polyacrylic acid/bentonite hydrogel with high ionic conductivity enables self-powered triboelectric wearable electronic devices.

Solid-state zinc-ion hybrid supercapacitors (ZHSCs) featuring hydrogel electrolytes have become ideal for large-scale flexible energy storage. However, existing polyacrylic acid (PAA) hydrogel electrolytes often lack the combined traits of ionic conductivity, mechanical robustness, and temperature tolerance. Herein, a versatile PAA-based hydrogel electrolyte (ACBH-Zn) containing a ZnCl2-cellulose solution and bentonite (BT) is delivered, facilitated by cooperative coordination bonds and hydrogen bonds. The coordination bonds between Zn2+ and -COOH of PAA, in conjunction with cellulose and BT, alongside the abundant hydrogen bonds within cellulose and PAA, are conducive to upgrading mechanical strength and ionic conductivity, while the BT's lamellar structure further provides sufficient ion migration channels. Consequently, the ACBH-Zn showcases exceptional mechanical properties, satisfying ionic conductivity (88.9 mS cm-1), and excellent temperature tolerance at -60 °C (30.3 mS cm-1). The ACBH-ZHSC, when assembled, attains a remarkable maximum energy density (323.4 Wh kg-1), maintaining an impressive capacity retention rate (92 %) even after undergoing 10,000 cycles at 10.0 A g-1. Furthermore, the assembled self-powered triboelectric wearable electronic device effectively converts mechanical energy from human movement into electrical energy, enabling efficient storage and utilization, and offering promising insights into the application of flexible wearable devices.

From Friction to Function: A High-Voltage Sliding Triboelectric Nanogenerator for Highly Efficient Energy Autonomous IoTs and Self-Powered Actuation.

An advanced energy autonomous system that simultaneously harnesses and stores energy on the same platform offers exciting opportunities for the near-future self-powered miniature electronics. However, achieving optimal synchronization between the power output of an energy harvester and the storage unit or integrating it seamlessly with real-time microelectronics to build a highly efficient energy autonomous system remains challenging. Herein, a unique bimetallic layered double hydroxide (LDH) based tribo-positive layer is introduced for a high-voltage sliding triboelectric nanogenerator (S-TENG) with an output voltage of ≈1485 V and power output of 250 µW, respectively. To demonstrate the potential of a self-charging power system, S-TENG is integrated with on-chip micro-supercapacitors (MSCs) as a storage unit. The MSC array effectively self-charged up to 4.8 V (within 220s), providing ample power to support micro-sensory systems. In addition, by utilizing the high-voltage output of the S-TENG, the efficient operation of electrostatic actuators and digital microfluidic (DMF) systems driven directly by simple mechanical motion is further demonstrated. Overall, this work can provide a solid foundation for the advancement of next-generation energy-autonomous systems.

Enhancing Photoelectric Response of Self-powered UV and Visible Detectors Using CuO/ZnO NRs Heterojunctions.

Understanding the development and performance of UV photodetectors is crucial, given their extensive applications in both military and civilian sectors. The evolution of self-powered photodetectors, especially those based on heterojunction nanostructures, has demonstrated significant potential for enhancing both device efficiency and functionality. By exploring the effects of material composition and structural design, can optimize these devices for improved photoelectric response and energy efficiency. In this study, we prepared the CuO/ZnO NRs heterojunction photodetector on an ITO substrate to enhance photoelectric response of UV detectors. The fabrication process utilized the hydrothermal method and the spin coating technique. The effect of CuO concentration on the optical response of the photodetector under UV radiation at wavelengths of 405 nm and 385 nm was investigated. The samples were characterized using FESSEM, XRD, EDX, and UV-Vis spectra. The device is further distinguished by its standard I-V curves and photocurrent-time curves, which demonstrate the device's behavior under various light conditions. The prepared thin films are polycrystalline, with CuO layers displaying monoclinic phases and ZnO layers exhibiting a hexagonal wurtzite phase. All samples have the potential to exhibit photovoltaic properties and self-powered capabilities. Furthermore, the I-V curve confirms that the photocurrent mechanism of these junctions adheres to the recombination standard, in addition to demonstrating correction behavior. A sample with a CuO concentration of 0.1 M shows the highest photosensitivity, reaching 340,700%, and a photocurrent gain (Iph/Idark) of 3,408 when exposed to light irradiation at 405 nm. Additionally, it exhibits a rapid response time of 0.8 s.

Deep-learning-assisted thermogalvanic hydrogel fiber sensor for self-powered in-nostril respiratory monitoring.

Direct and consistent monitoring of respiratory patterns is crucial for disease prognostication. Although the wired clinical respiratory monitoring apparatus can operate accurately, the existing defects are evident, such as the indispensability of an external power supply, low mobility, poor comfort, and limited monitoring timeframes. Here, we present a self-powered in-nostril hydrogel sensor for long-term non-irritant anti-interference respiratory monitoring, which is developed from a dual-network binary-solvent thermogalvanic polyvinyl alcohol hydrogel fiber (d = 500 µm, L=30 mm) with Fe2+/Fe3+ ions serving as a redox couple, which can generate a thermoelectrical signal in the nasal cavity based on the temperature difference between the exhaled gas and skin as well as avoid interference from the external environment. Due to strong hydrogen bonding between solvent molecules, the sensor retains over 90 % of its moisture after 14 days, exhibiting great potential in wearable respiratory surveillance. With the assistance of deep learning, the hydrogel fiber-based respiration monitoring strategy can actively recognize seven typical breathing patterns with an accuracy of 97.1 % by extracting the time sequence and dynamic parameters of the thermoelectric signals generated by respiration, providing an alert for high-risk respiratory symptoms. This work demonstrates the significant potential of thermogalvanic gels for next-generation wearable bioelectronics for early screening of respiratory diseases.

Optoelectronics Interfaces for a VLC System for UHD Audio-Visual Content Transmission in a Passenger Van: HW Design.

This work aims to provide the hardware (HW) design of the optoelectronics interfaces for a visible-light communication (VLC) system that can be employed for several use cases. Potential applications include the transmission of ultra-high-definition (UHD) streaming video through existing reading lamps installed in passenger vans. In this use case, visible light is employed for the downlink, while infrared light is used for the uplink channel, acting as a remote controller. Two primary components -a Light Fidelity (LiFi) router and a USB dongle-were designed and implemented. The 'LiFi Router', handling the downlink channel, comprises components such as a visible Light-Emitting Diode (LED) and an infrared receiver. Operating at a supply voltage of 12 V and consuming current at 920 mA, it is compatible with standard voltage buses found in transport vehicles. The 'USB dongle', responsible for the uplink, incorporates an infrared LED and a receiver optimized for visible light. The USB dongle works at a supply voltage of 5 V and shows a current consumption of 1.12 A, making it well suited for direct connection to a universal serial bus (USB) port. The bandwidth achieved for the downlink is 11.66 MHz, while the uplink's bandwidth is 12.27 MHz. A system competent at streaming UHD video with the feature of being single-input multiple-output (SIMO) was successfully implemented via the custom hardware design of the optical transceivers and optoelectronics interfaces. To ensure the system's correct performance at a distance of 110 cm, the minimum signal-to-noise ratio (SNRmin) for both optical links was maintained at 10.74 dB. We conducted a proof-of-concept test of the VLC system in a passenger van and verified its optimal operation, effectively illustrating its performance in a real operating environment. Exemplifying potential implementations possible with the hardware system designed in this work, a bit rate of 15.2 Mbps was reached with On-Off Keying (OOK), and 11.25 Mbps was obtained with Quadrature Phase Shift Keying (QPSK) using Orthogonal Frequency-Division Multiplexing (OFDM) obtaining a bit-error rate (BER) of 3.3259 × 10-5 in a passenger van at a distance of 72.5 cm between the LiFi router and the USB dongle. As a final addition, a solar panel was installed on the passenger van's roof to power the user's laptop and the USB dongle via a power bank battery. It took 13.4 h to charge the battery, yielding a battery life of 22.3 h. This characteristic renders the user's side of the system entirely self-powered.

Signal amplification strategy based on target-controlled release of mediator for ultrasensitive self-powered biosensing of acetamiprid.

Self-powered biosensors with high sensitivity have garnered significant interest for their potential applications in the realm of portable sensing. Herein, a self-powered biosensor with a novel signal amplification strategy was developed by integrating target-controlled release of mediator with an enzyme biofuel cell for the ultrasensitive detection of acetamiprid (ACE). Zeolitic imidazolate framework-67 was utilized as both a nanocontainer for capturing the electron mediator 2,2'-azidobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and a precursor for the synthesis of cobalt nanoparticles/nitrogen, sulfur-codoped carbon nanotubes (Co NPs/NS-CNTs), which were employed as the electrode material for constructing both the glucose oxidase-based bioanode and the laccase-based biocathode. The target analyte ACE can specifically bind to its aptamer, leading to the release of ABTS, which cyclically participates in the catalytic reaction of the biocathode, thereby amplifying the electrochemical signal. By leveraging the benefits of ABTS cyclic catalysis and the effective electrocatalysis of bioelectrodes based on Co NPs/NS-CNTs, the self-powered biosensor has a broad detection range of 0.1-1000 fM and a low detection limit of 25 aM toward ACE. The proposed signal amplification approach presents a promising strategy for enhancing sensitivity and enabling portable analysis in applications of food safety, environmental monitoring, and medical diagnostics.

Spin-Enhanced Self-Powered Light Helicity Detecting Based on Vertical WSe2-CrI3 p-n Heterojunction.

Two-dimensional (2D) magnetic semiconductors offer an intriguing platform for investigating magneto-optoelectronic properties and hold immense potential in developing prospective devices when they are combined with valley electronic materials like 2D transition-metal dichalcogenides. Herein, we report various magneto-optoelectronic response features of the vertical hBN-FLG-CrI3-WSe2-FLG-hBN van der Waals heterostructure. Through a sensible layout and exquisite manipulation, an hBN-FLG-CrI3-FLG-hBN heterostructure was also fabricated on identical CrI3 and FLGs for better comparison. Our results show that the WSe2-CrI3 heterostructure, acting as a p-n heterojunction, has advantageous capability in light detection, especially in self-powered light helicity detecting. In the WSe2-CrI3 heterojunction, the absolute value of photocurrent IPH exhibits obvious asymmetry with respect to the bias V, with the IPH of reversely biased WSe2-CrI3 p-n heterojunction being larger. When the CrI3 is fully spin-polarized under a 3 T magnetic field, the reversely biased WSe2-CrI3 heterojunction exhibits advantageous capability in light helicity detecting. Both the short-circuit currents ISC and IPH show one-cycle fluctuation behaviors when the quarter-wave plate rotates 180°, and the corresponding photoresponsivity helicities can be as high as 18.0% and 20.1%, respectively. We attribute the spin-enhanced photovoltaic effect in the WSe2-CrI3 heterojunction and its contribution to circularly polarized light detection to the coordination function of the spin-filter CrI3, the valley electronic monolayer WSe2, and the spin-dependent charge transfer between them. Our work helps us understand the interplay between the magnetic and optoelectronic properties of WSe2-CrI3 heterojunctions and promotes the developing progress of prospective 2D spin optoelectronic devices.