Biomimetic synergistic effect of redox site and Lewis acid for construction of efficient artificial enzyme.

In enzymatic catalysis, the redox site and Lewis acid are the two main roles played by metal to assist amino acids. However, the reported enzyme mimics only focus on the redox-active metal as redox site, while the redox-inert metal as Lewis acid has, to the best of our knowledge, not been studied, presenting a bottleneck of enzyme mimics construction. Based on this, a series of highly efficient MVO·nHO peroxidase mimics with vanadium as redox site and alkaline-earth metal ion (M) as Lewis acid are reported.

DNAzyme-RCA-based colorimetric and lateral flow dipstick assays for the point-of-care testing of exosomal m5C-miRNA-21.

Methylation of microRNAs (miRNAs) is a post-transcriptional modification that affects miRNA activity by altering the specificity of miRNAs to target mRNAs. Abnormal methylation of miRNAs in cancer suggests their potential as a tumor marker. However, the traditional methylated miRNA detection mainly includes mass spectrometry, sequencing and others; complex procedures and reliance on large instruments greatly limit their application in point-of-care testing (POCT).

Combined Molecular and Morphological Imaging of CTCs for HER2-Targeted Chemotherapy Guidance.

Since biomolecules change dynamically with tumor evolution and drug treatment, it is necessary to confirm target molecule expression in real time for effective guidance of subsequent chemotherapy treatment. However, current methods to confirm target proteins require complex processing steps and invasive tissue biopsies, limiting their clinical utility for targeted treatment monitoring. Here, CTCs, as a promising liquid biopsy source, were used to molecularly characterize the target protein HER2.

Single-Molecule Imaging of Reactive Oxygen Species on a Semiconductor Nano-Heterostructure for Understanding Photocatalytic Heterogeneity in Aqueous.

We constructed a single-molecule fluorescence imaging technique to monitor the spatiotemporal distribution of the hydroxyl radical (•OH) on TiO-attached multiwalled carbon nanotubes (TiO-MWCNTs) in aqueous. We found the heterogeneous distribution of •OH is closely related to the composition and heterostructure of the catalysts. The dynamic •OH production rate was evaluated by counting the single-molecule fluorescent bursts.

Responsive Dual-Targeting Exosome as a Drug Carrier for Combination Cancer Immunotherapy.

Recently, combination immunotherapy, which incorporates the activation of the immune system and inhibition of immune escape, has been proved to be a new powerful strategy for more efficient tumor suppression compared to monotherapy. However, the major challenge is how to integrate multiple immune drugs together and efficiently convey these drugs to tumor sites. Although a variety of nanomaterials have been exploited as carriers for targeting tumor issues and the delivery of multiple drugs, their potential toxicity, immune rejection, and stability are still controversial for clinical application.

Sputum-Based Tumor Fluid Biopsy: Isolation and High-Throughput Single-Cell Analysis of Exfoliated Tumor Cells for Lung Cancer Diagnosis.

Timely and effective diagnosis is of great significance for improving the survival rate of lung cancer patients. Although histopathology is the main diagnostic tool among the existing methods for lung cancer diagnosis, it is not suitable for high-risk groups, early lung cancer patients, patients with advanced-stage disease, and other situations wherein tumor tissues cannot be obtained. In view of this, we proposed an innovative lung cancer diagnosis method employing for the first time a microfluidic technology for high-efficiency isolation and high-throughput single-cell analysis of exfoliated tumor cells (ETCs) in sputum.

Consecutive Sorting and Phenotypic Counting of CTCs by an Optofluidic Flow Cytometer.

Circulating tumor cell (CTC) analysis has been approved for cancer diagnosis and monitoring. However, efficient sorting and high-through phenotypic counting of CTCs from peripheral blood is still a challenge. In this manuscript, we propose an optofluidic flow cytometer (OFCM), which integrates a multistage microfluidic chip and a four-color fluorescence detection system.

High-throughput and ultra-sensitive single-cell profiling of multiple microRNAs and identification of human cancer.

We established an efficient method for single-cell miRNA analysis by droplet microfluidics, which has high sensitivity of single molecule detection and high throughput. Single-cell analysis of multiple miRNAs in various cells shows that miRNA expression is closely related to cancer type. CTC analysis shows that the method is applicable for rare cell analysis.

Single-Cell Phenotypic Profiling of CTCs in Whole Blood Using an Integrated Microfluidic Device.

Single-cell phenotypic profiling of circulating tumor cells (CTCs) in the blood of cancer patients can reveal vital tumor biology information. Even though various approaches have been provided to enrich and detect CTCs, it remains challenging for consecutive CTC sorting, enumeration, and single-cell characterizations. Here, we report an integrated microfluidic device (IMD) for single-cell phenotypic profiling of CTCs that enables automated CTCs sorting from whole blood following continuous single-cell phenotypic analysis while satisfying the requirements of both high purity (92 ± 3%) of cell sorting and high-throughput processing capacity (5 mL whole blood/3 h).

In situ fluorescent profiling of living cell membrane proteins at a single-molecule level.

We propose a signal amplification method that enables visualization analysis of membrane proteins on living cells at a single-molecule level. Using the proposed method, we achieved imaging of PTK7 membrane proteins on HeLa cells and analyzed the down-regulated expression of EpCAM on the MCF-7 cell surface during epithelial-mesenchymal transition (EMT).

Dynamic fluorescent imaging analysis of mitochondrial redox in single cells with a microfluidic device.

The redox balance in cellular mitochondria is closely related to the physiological and pathological processes of the body. When exposed to external stimuli, the redox state in cells changes dynamically, and presents cell heterogeneity, which creates a need for techniques that can make dynamic and reversible visual analysis of redox in mitochondria at single-cell level. Here we describe a method for single-cell redox analysis based on a microfluidic device combing with a reversible fluorescent probe (Cy-O-ebselen), that enables online culture, labelling and dynamic fluorescent imaging analysis of mitochondrial redox (HO/GSH) change.

Visible Light-Driven Self-Powered Device Based on a Straddling Nano-Heterojunction and Bio-Application for the Quantitation of Exosomal RNA.

This paper reports the design and fabrication of a self-powered biosensing device based on TiO nanosilks (NSs)@MoS quantum dots (QDs) and demonstrates a bioapplication for the quantitative detection of exosomal RNA ( Homo sapiens HOXA distal transcript antisense RNA, HOTTIP). This self-powered device features enhanced power output compared to TiO NSs alone. This is attributed to the formation of a heterojunction structure with suitable band offset derived from the hybridization between TiO NSs and MoS QDs, i.

In situ fluorescence monitoring of diagnosis and treatment: a versatile nanoprobe combining tumor targeting based on MUC1 and controllable DOX release by telomerase.

We have constructed versatile drug-loaded nanoprobes capable of responding to both MUC1 and telomerase and achieving intracellular drug release. Besides, the synthesized drug-loaded nanoprobes can realize the in situ imaging observation of the whole process of nanoprobes targeting the tumor cell membrane, the transmembrane entering the cytoplasm and the release of DOX into the cell nucleus.

Highly Sensitive Fluorescence Imaging of Zn and Cu in Living Cells with Signal Amplification Based on Functional DNA Self-Assembly.

Intracellular trace Zn and Cu play important roles in the regulation of cell function. Considering the limitations of existing metal ion detection methods regarding sensitivity and applicability to living cells, an amplification strategy based on functional DNA self-assembly under DNAzyme catalysis to improve the sensitivity of intracellular Zn and Cu imaging is reported. In this process, metal ions as cofactor can activate the catalysis of DNAzyme to shear substrate chains, and each broken substrate chain can initiate consecutive hybridizations of hairpin probes (Hx) labeled with fluorophore, which can reflect the information on a single metal ion with multiple fluorophores.

Fluorescent analysis of bioactive molecules in single cells based on microfluidic chips.

Single-cell analysis of bioactive molecules is an essential strategy for a better understanding of cell biology, exploring cell heterogeneity, and improvement of the ability to detect early diseases. In single-cell analysis, highly efficient single-cell manipulation techniques and high-sensitive detection schemes are in urgent need. The rapid development of fluorescent analysis techniques combined with microfluidic chips have offered a widely applicable solution.

Simultaneous Single-Cell Analysis of Na, K, Ca, and Mg in Neuron-Like PC-12 Cells in a Microfluidic System.

Various intracellular metal ions have closely related functional roles in the nervous system. An excess or deficiency of essential metal ions can contribute to neurodegenerative diseases. Thus, the detection of various metal ions in neurons is important for diagnosing and monitoring these diseases.

Synthesis of Few-Atomic-Layer BN Hollow Nanospheres and Their Applications as Nanocontainers and Catalyst Support Materials.

In this work, few-atomic-layer boron nitride (BN) hollow nanospheres were directly synthesized via a modified CVD method followed by subsequent high-temperature degassing treatment. The encapsulated impurities in the hollow nanospheres were effectively removed during the reaction process. The BN shells of most nanospheres consisted of 2-6 atomic layers.

Large-Scale Synthesis of Few-Layer F-BN Nanocages with Zigzag-Edge Triangular Antidot Defects and Investigation of the Advanced Ferromagnetism.

Investigation of light-element magnetism system is essential in fundamental and practical fields. Here, few-layer (∼3 nm) fluorinated hexagonal boron nitride (F-BN) nanocages with zigzag-edge triangular antidot defects were synthesized via a facile one-step solid-state reaction. They are free of metallic impurities confirmed by X-ray photoelectron spectroscopy, electron energy loss spectroscopy, and inductively coupled plasma atomic emission spectroscopy.

Pressure-Induced Oriented Attachment Growth of Large-Size Crystals for Constructing 3D Ordered Superstructures.

Oriented attachment (OA), a nonclassical crystal growth mechanism, provides a powerful bottom-up approach to obtain ordered superstructures, which also demonstrate exciting charge transmission characteristic. However, there is little work observably pronouncing the achievement of 3D OA growth of crystallites with large size (e.g.

Boron nitride ultrathin fibrous nanonets: one-step synthesis and applications for ultrafast adsorption for water treatment and selective filtration of nanoparticles.

Novel boron nitride (BN) ultrathin fibrous networks are firstly synthesized via an one-step solvothermal process. The average diameter of BN nanofibers is only ~8 nm. This nanonets exhibit excellent performance for water treatment.