Enhanced Electrochemical Detection Of Multi-Heavy Metal Ions Using A Biopolymer-Coated Planar Carbon Electrode

In this study, a chitosan biopolymer-coated planar carbon electrode was developed for in situ determination of heavy metals (Zn2+ and Pb2+) using square wave anodic stripping voltammetry (SWASV). The experimental conditions were optimized with respect to deposition time, amplitude and frequency. With 300 s deposition time, the heavy metal stripping was conducted at 0.05 V pulse amplitude, 20 Hz pulse frequency, and 0.004 V square wave step voltage in 0.1M acetate buffer at pH 4.6. Two distinguished peaks were observed at-0.86 and-0.37V, which are associated with the stripping of Zn2+ and Pb2+, respectively. Limit of detection (LOD) was 0.6 and 1 ppb for Zn2+ and Pb2+, respectively, and the relative standard deviations (RSD) for repetitive measurements of Zn2+ and Pb2+ were in the range of 4.8-5.4 % (n=30 with two identical electrodes). Overall, the developed biopolymer-coated carbon electrode exhibited excellent representativeness and reproductivity for in situ multi heavy metal ions detection in spiked samples, holding a great promise for on-site testing of heavy metals in drinking water

Synthesis Strategies and Nanoarchitectonics for High-Performance Transition Metal Dichalcogenide Thin Film Field-effect Transistors

Transition metal dichalcogenides (TMDC) exhibit highly superior electrical properties and are typically obtained through mechanical exfoliation. This method has significant limitations, however, such as patterning issues and non-uniformity, which hinder their application in integrated circuits as transistors and array pixel displays. To overcome these challenges, various large-scale deposition methods have been developed. In this review, we introduce five major methods for TMDC deposition: chemical vapor deposition, physical vapor deposition, atomic layer deposition, pulsed laser deposition, and ink-jet printing. An overview of each method is provided in the following order: surface analysis, electrical characteristics, and limitations of each method are discussed. Furthermore, we present three key strategies for an advanced device fabrication using the discussed deposition methods. By implementing these strategies, we can accelerate the development of highly crystalline and scalable TMDC thin films, which are essential for producing advanced electronic devices with improved performance. Owing to recent technological advancements, TMDC devices have the potential to become the leading material for next-generation semiconductor devices. These devices can be specifically designed and optimized for innovative applications

Wearable and implantable bioelectronics as eco‐friendly and patient‐friendly integrated nanoarchitectonics for next‐generation smart healthcare technology

Abstract Since the beginning of human history, the demand for effective healthcare systems for diagnosis and treatment of health problems has grown steadily. However, traditional centralized healthcare requires hospital visits, making in‐time and long‐term healthcare challenging. Bioelectronics has shown potential in patient‐friendly healthcare owing to the rapid advances in diverse fields of biology and electronics. In particular, wearable and implantable bioelectronics have emerged as an alternative or adjunct to conventional healthcare. To develop into next‐generation healthcare systems, however, custom designs for biological targets with a deepened understanding of the intrinsic features of the target are essential. In addition, bioelectronic systems must be designed eco‐friendly for sustainable healthcare. In this review, bioelectronics as eco‐friendly and patient‐friendly integrated nanoarchitectonics as next‐generation smart healthcare technology are described. For an in‐depth understanding of biological targets and guidelines for target‐tailored design, we discuss target‐specific considerations and relevant key parameters of bioelectronic systems with the representative examples

Enhanced Moisture-Reactive Hydrophilic-PTFE-Based Flexible Humidity Sensor for Real-Time Monitoring

Flexible sensors connected to cell phones are a promising technology that can aid in continuously monitoring signals in our daily lives, such as an individual’s health status and information from buildings, farms, and industry. Among such signals, real-time humidity monitoring is crucial to a comfortable life, as human bodies, plants, and industrial environments require appropriate humidity to be maintained. We propose a hydrophilic polytetrafluoroethylene (H-PTFE)-based flexible humidity sensor integrated with readout circuitry, wireless communication, and a mobile battery. To enhance its sensitivity, linearity, and reliability, treatment with sodium hydroxide implements additional hydroxyl (OH) groups, which further enhance the sensitivity, create a strong linearity with respect to variations in relative humidity, and produce a relatively free hysteresis. Furthermore, to create robust mechanical stability, cyclic upward bending was performed for up to 3000 cycles. The overall electrical and mechanical results demonstrate that the flexible real-time H-PTFE humidity sensor system is suitable for applications such as wearable smart devices

High-Performance Non-Volatile InGaZnO Based Flash Memory Device Embedded with a Monolayer Au Nanoparticles

Non-volatile memory (NVM) devices based on three-terminal thin-film transistors (TFTs) have gained extensive interest in memory applications due to their high retained characteristics, good scalability, and high charge storage capacity. Herein, we report a low-temperature (<100 °C) processed top-gate TFT-type NVM device using indium gallium zinc oxide (IGZO) semiconductor with monolayer gold nanoparticles (AuNPs) as a floating gate layer to obtain reliable memory operations. The proposed NVM device exhibits a high memory window (ΔVth) of 13.7 V when it sweeps from −20 V to +20 V back and forth. Additionally, the material characteristics of the monolayer AuNPs (floating gate layer) and IGZO film (semiconductor layer) are confirmed using transmission electronic microscopy (TEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS) techniques. The memory operations in terms of endurance and retention are obtained, revealing highly stable endurance properties of the device up to 100 P/E cycles by applying pulses (±20 V, duration of 100 ms) and reliable retention time up to 104 s. The proposed NVM device, owing to the properties of large memory window, stable endurance, and high retention time, enables an excellent approach in futuristic non-volatile memory technology

Enhanced Moisture-Reactive Hydrophilic-PTFE-Based Flexible Humidity Sensor for Real-Time Monitoring

Flexible sensors connected to cell phones are a promising technology that can aid in continuously monitoring signals in our daily lives, such as an individual’s health status and information from buildings, farms, and industry. Among such signals, real-time humidity monitoring is crucial to a comfortable life, as human bodies, plants, and industrial environments require appropriate humidity to be maintained. We propose a hydrophilic polytetrafluoroethylene (H-PTFE)-based flexible humidity sensor integrated with readout circuitry, wireless communication, and a mobile battery. To enhance its sensitivity, linearity, and reliability, treatment with sodium hydroxide implements additional hydroxyl (OH) groups, which further enhance the sensitivity, create a strong linearity with respect to variations in relative humidity, and produce a relatively free hysteresis. Furthermore, to create robust mechanical stability, cyclic upward bending was performed for up to 3000 cycles. The overall electrical and mechanical results demonstrate that the flexible real-time H-PTFE humidity sensor system is suitable for applications such as wearable smart devices