Applications of flexible electronics related to cardiocerebral vascular system.

Ensuring accessible and high-quality healthcare worldwide requires field-deployable and affordable clinical diagnostic tools with high performance. In recent years, flexible electronics with wearable and implantable capabilities have garnered significant attention from researchers, which functioned as vital clinical diagnostic-assisted tools by real-time signal transmission from interested targets in vivo. As the most crucial and complex system of human body, cardiocerebral vascular system together with heart-brain network attracts researchers inputting profuse and indefatigable efforts on proper flexible electronics design and materials selection, trying to overcome the impassable gulf between vivid organisms and rigid inorganic units. This article reviews recent breakthroughs in flexible electronics specifically applied to cardiocerebral vascular system and heart-brain network. Relevant sensor types and working principles, electronics materials selection and treatment methods are expounded. Applications of flexible electronics related to these interested organs and systems are specially highlighted. Through precedent great working studies, we conclude their merits and point out some limitations in this emerging field, thus will help to pave the way for revolutionary flexible electronics and diagnosis assisted tools development.

Manipulation with sound and vibration: A review on the micromanipulation system based on sub-MHz acoustic waves.

Manipulation of micro-objects have been playing an essential role in biochemical analysis or clinical diagnostics. Among the diverse technologies for micromanipulation, acoustic methods show the advantages of good biocompatibility, wide tunability, a label-free and contactless manner. Thus, acoustic micromanipulations have been widely exploited in micro-analysis systems. In this article, we reviewed the acoustic micromanipulation systems that were actuated by sub-MHz acoustic waves. In contrast to the high-frequency range, the acoustic microsystems operating at sub-MHz acoustic frequency are more accessible, whose acoustic sources are at low cost and even available from daily acoustic devices (e.g. buzzers, speakers, piezoelectric plates). The broad availability, with the addition of the advantages of acoustic micromanipulation, make sub-MHz microsystems promising for a variety of biomedical applications. Here, we review recent progresses in sub-MHz acoustic micromanipulation technologies, focusing on their applications in biomedical fields. These technologies are based on the basic acoustic phenomenon, such as cavitation, acoustic radiation force, and acoustic streaming. And categorized by their applications, we introduce these systems for mixing, pumping and droplet generation, separation and enrichment, patterning, rotation, propulsion and actuation. The diverse applications of these systems hold great promise for a wide range of enhancements in biomedicines and attract increasing interest for further investigation.

Constructing Oxygen-Related Defects in Carbon Nanodots with Janus Optical Properties: Noninvasive NIR Fluorescent Imaging and Effective Photocatalytic Therapy.

Noninvasive fluorescence (FL) imaging and high-performance photocatalytic therapy (PCT) are opposing optical properties that are difficult to combine in a single material system. Herein, a facile approach to introducing oxygen-related defects in carbon dots (CDs) via post-oxidation with 2-iodoxybenzoic acid is reported, in which some nitrogen atoms are substituted by oxygen atoms. Unpaired electrons in these oxygen-related defects rearrange the electronic structure of the oxidized CDs (ox-CDs), resulting in an emerging near-infrared (NIR) absorption band. These defects not only contribute to enhanced NIR bandgap emission but also act as trappers for photoexcited electrons to promote efficient charge separation on the surface, leading to abundant photo-generated holes on the ox-CDs surface under visible-light irradiation. Under white LED torch irradiation, the photo-generated holes oxidize hydroxide to hydroxyl radicals in the acidification of the aqueous solution. In contrast, no hydroxyl radicals are detected in the ox-CDs aqueous solution under 730 nm laser irradiation, indicating noninvasive NIR FL imaging potential. Utilizing the Janus optical properties of the ox-CDs, the in vivo NIR FL imaging of sentinel lymph nodes around tumors and efficient photothermal enhanced tumor PCT are demonstrated.

Visible-light-induced strong oxidation capacity of metal-free carbon nanodots through photo-induced surface reduction for photocatalytic antibacterial and tumor therapy.

Biocompatible metal-free carbon dots (CDs) with good photo-induced strong oxidation capacity in aqueous solutions are scarce for high-performance photocatalytic antibacterial and tumor therapy. In this work, we achieved effective visible light-induced cell death and antibacterial performance based on biocompatible metal-free CDs. The visible-light-induced reducing ability of the surface electron-withdrawing structure of the CDs allowed for the remaining photo-induced holes with high oxidation capacity to oxidize water molecules and generate hydroxyl radicals. Antibiotic-resistant bacteria were effectively inhibited by the CDs under xenon lamp irradiation with 450 nm long pass filter. Moreover, CD-based tumor photocatalytic therapy in mice was achieved using a xenon lamp with 450 nm long pass filter (0.3 W cm-2).

Magnetism-Resolved Separation and Fluorescence Quantification for Near-Simultaneous Detection of Multiple Pathogens.

In the modern era of molecular evidence-based medicine and advanced biomedical technologies, the rapid, sensitive and specific assay of multiple pathogens is critical to, but largely absent from, clinical practice. Therefore, to improve the current ordinary separation and collection method, we report herein a strategy of magnetism-resolved separation and fluorescence quantification for near-simultaneous detection of multiple pathogens, followed by the direct antimicrobial susceptibility testing (AST). To accomplish this strategy, we utilized aptamer-modified fluorescent-magnetic multifunctional nanoprobes (apt-FMNPs). FMNPs with intriguing different magnetic responses and excellent fluorescence quality were first self-assembled based on metal coordination interaction using (3-mercaptopropyl) trimethoxysilane, magnetic γ-Fe2O3, and fluorescent quantum dots as matrix components. Then, aptamers, which specific to target pathogens of Escherichia coli O157:H7 ( E. coli) and Salmonella typhimurium ( S. typ), were conjugated with FMNPs to yield apt-FMNPs nanoprobes for multiple pathogens assay. Based on the discrepant magnetic response of pathogen@nanoprobes complex under the identical external magnetic field, the model bacteria were fished out by magnetic adsorption at different time points and subjected to fluorescence quantification with good linear ranges and detection limits within 1h. Multiple pathogens spiked in real samples were also effectively detected by the apt-FMNPs and sequentially fished out for AST assay, which showed similar results to that for pure pathogens. The apt-FMNPs-based strategy of near-simultaneous detection of multiple pathogens shows promise for the potential application in the diagnosis and treatment of pathogen-related infectious diseases.