As an essential part of solid-state lithium-ion batteries, solid electrolytes are receiving increasing interest. Among all solid electrolytes, garnet-type Li₇La₃Zr₂O₁₂ (LLZO) has proven to be one of the most promising electrolytes because of its high ionic conductivity at room temperature, low activation energy, good chemical and electrochemical stability, and wide potential window. Since the first report of LLZO, extensive research has been done in both experimental investigations and theoretical simulations aiming to improve its performance and make LLZO a feasible solid electrolyte. These include developing different methods for the synthesis of LLZO, using different crucibles and different sintering temperatures to stabilize the crystal structure, and adopting different methods of cation doping to achieve more stable LLZO with a higher ionic conductivity and lower activation energy. It also includes intensive efforts made to reveal the mechanism of Li ion movement and understand its determination of the ionic conductivity of the material through molecular dynamic simulations. Nonetheless, more insightful study is expected in order to obtain LLZO with a higher ionic conductivity at room temperature and further improve chemical and electrochemical stability, while optimal multiple doping is thought to be a feasible and promising route. This review summarizes recent progress in the investigations of crystal structure and preparation of LLZO, and the impacts of doping on the lithium ionic conductivity of LLZO.

Electrodeposition, which features low cost, easy scale-up, good control in the composition and great flexible substrate compatibility, is a favorable technique for producing thin films. This paper reviews the use of the electrodeposition technique for the fabrication of several representative chalcogenides that have been widely used in photovoltaic devices. The review focuses on narrating the mechanisms for the formation of films and the key factors that affect the morphology, composition, crystal structure and electric and photovoltaic properties of the films. The review ends with a remark section addressing some of the key issues in the electrodeposition method towards creating high quality chalcogenide films.

Major advances in cancer control can be greatly aided by early diagnosis and effective treatment in its pre-invasive state. Lung cancer (small cell and non-small cell) is a leading cause of cancer-related deaths among both men and women around the world. A lot of research attention has been directed toward diagnosing and treating lung cancer. A common method of lung cancer treatment is based on COX-2 (cyclooxygenase-2) inhibitors. This is because COX-2 is commonly overexpressed in lung cancer and also the abundance of its enzymatic product prostaglandin E2 (PGE₂). Instead of using traditional COX-2 inhibitors to treat lung cancer, here, we introduce a new anti-cancer strategy recently developed for lung cancer treatment. It adopts more abundant omega-6 (ω-6) fatty acids such as dihomo-γ-linolenic acid (DGLA) in the daily diet and the commonly high levels of COX-2 expressed in lung cancer to promote the formation of 8-hydroxyoctanoic acid (8-HOA) through a new delta-5-desaturase (D5Di) inhibitor. The D5Di does not only limit the metabolic product, PGE_2, but also promote the COX-2 catalyzed DGLA peroxidation to form 8-HOA, a novel anti-cancer free radical byproduct. Therefore, the measurement of the PGE₂ and 8-HOA levels in cancer cells can be an effective method to treat lung cancer by providing in-time guidance. In this paper, we mainly report on a novel sensor, which is based on a newly developed functionalized nanomaterial, 2-dimensional nanosheets, or Ti₃C₂ MXene. The preliminary results have proven to sensitively, selectively, precisely, and effectively detect PGE₂ and 8-HOA in A549 lung cancer cells. The capability of the sensor to detect trace level 8-HOA in A549 has been verified in comparison with the traditional gas chromatography–mass spectrometry (GC–MS) method. The sensing principle could be due to the unique structure and material property of Ti₃C₂ MXene: a multilayered structure and extremely large surface area, metallic conductivity, and ease and versatility in surface modification. All these make the Ti₃C₂ MXene-based sensor selectively adsorb 8-HOA molecules through effective charge transfer and lead to a measurable change in the conductivity of the material with a high signal-to-noise ratio and excellent sensitivity.

The acetone content in the exhaled breath of individuals as a biomarker of diabetes has become widely studied as a non-invasive means of quantifying blood glucose levels. This calls for development of sensors for the quantitative analysis of trace concentration of acetone, which is presents in the human exhaled breath. Traditional gas detection systems, such as the Gas Chromatography/Mass Spectrometry and several types of chemiresistive sensors are currently being used for this purpose. However, these systems are known to have limitations of size, cost, response time, operating conditions, and consistent accuracy. An ideal breath acetone sensor should provide solutions to overcome the above limitations and provide good stability and reliability. It should be a simple and portable detection system of good sensitivity, selectivity that is low in terms of both cost and power consumption. To achieve this goal, in this paper, we report a new sensing nanomaterial made by nanocomposite, 1D KWO (K₂W₇O₂₂) nanorods/2D Ti₃C₂T_x nanosheets, as the key component to design an acetone sensor. The preliminary result exhibits that the new nanocomposite has an improved response to acetone, with 10 times higher sensitivity comparing to KWO-based sensor, much better tolerance of humidity interference and enhanced stability for multiple months. By comparing with other nanomaterials: Ti₃C₂, KWO, and KWO/Ti₃C₂T_x nanocomposites with variable ratio of KWO and Ti₃C₂T_x from 1:1, 1:2, 1:5, 2:1, 4:1, and 9:1, the initial results confirm the potential of the novel KWO/Ti₃C₂ (2:1) nanocomposite to be an excellent sensing material for application in sensitive and selective detection of breath acetone for diabetics health care and prevention.

Diabetes is one of the most rapidly-growing chronic diseases in the world. Acetone, a volatile organic compound in exhaled breath, shows a positive correlation with blood glucose and has proven to be a biomarker for type-1 diabetes. Measuring the level of acetone in exhaled breath can provide a non-invasive, low risk of infection, low cost, and convenient way to monitor the health condition of diabetics. There has been continuous demand for the improvement of this non-invasive, sensitive sensor system to provide a fast and real-time electronic readout of blood glucose levels. A novel nanostructured K₂W₇O₂₂ has been recently used to test acetone with concentration from 0 parts-per-million (ppm) to 50 ppm at room temperature. The results revealed that a K₂W₇O₂₂ sensor shows a sensitive response to acetone, but the detection limit is not ideal due to the limitations of the detection system of the device. In this paper, we report a K₂W₇O₂₂ sensor with an improved sensitivity and detection limit by using an optimized circuit to minimize the electronic noise and increase the signal to noise ratio for the purpose of weak signal detection while the concentration of acetone is very low.

A newly synthesized nanomaterial known as K_xW₇O₂₂ (K_xWO) exhibits a stable room-temperature ferroelectric property. This unique ferroelectric property has revealed that K_xWO is a promising material for application in a breath sensor, which can be used for patients to monitor their daily health condition and diagnose disease at every early stage with low cost, convenience, and non-invasion. In this study, we successfully synthesized nano-structured K_xWO through a low cost but high yield hydrothermal method. The sensing response of K_xWO to acetone is examined based on a chemiresistive effect. For the first time, we systematically studied how material structures and the component, potassium (K), can affect K_xWO-based sensing performance. The results indicate that the low temperature ferroelectric property of K_xWO causes an excellent response to acetone, which is the biomarker for diabetes. The lowest detection limit can be down to 0.1 ppm and the K_xWO-based sensor can operate at room temperature. In addition, the K_x component K_xWO and its crystal structure also play an important role in improving its sensing performance. Our results provide advanced research in (1) exploring the study of K_xWO material properties by tailoring the concentration of the potassium in K_xWO and introducing the surfactant Pluronic L-121 in the growing process, and (2) optimizing K_xWO sensing performance by controlling its material properties.