Turn-On NIR-II Polymer Dots with Large Stokes Shift for In Vivo Visualizing Dynamical Brain Zinc in Alzheimer's Disease Mouse.

It is a critical and broad prospect to evaluate ion levels and monitor their dynamic changes in the brain for early diagnosis, in-depth mechanism investigation, and accurate staging of neurodegenerative diseases including Alzheimer's disease (AD). It is still a great challenge to in vivo track Zn levels in the brain by fluorescence imaging due to the drawbacks including short emission wavelength, poor selectivity and sensitivity, and unfavorable penetration across the blood-brain barrier (BBB) for currently developed fluorescent probes. We herein engineer a fluorescent probe with a large Stokes shift of 256 nm, NNDPTQ Pdots, which display substantial Zn-specific turn-on response in the NIR II region with the longest emission of 1064 nm up to now.

Reversible Modulation of Cell-Cell Interactions Using Electrochemistry.

Cell-cell interactions play an important role in many biological processes, and various methods have been developed for controlling the cell-cell interactions. However, the effective and rapid control of intercellular interactions remains challenging. Herein, we report a novel, rapid, and effective electrochemical strategy without destroying the basic life processes for the dynamic control of intercellular interactions via liposome fusion.

NIR-II-Responsive Versatile Nanozyme Based on HO Cycling and Disrupting Cellular Redox Homeostasis for Enhanced Synergistic Cancer Therapy.

Disturbing cellular redox homeostasis within malignant cells, particularly improving reactive oxygen species (ROS), is one of the effective strategies for cancer therapy. The ROS generation based on nanozymes presents a promising strategy for cancer treatment. However, the therapeutic efficacy is limited due to the insufficient catalytic activity of nanozymes or their high dependence on hydrogen peroxide (HO) or oxygen.

Cascade Self-Generation of Carbon Monoxide Triggered by Photoinduced Holes for Efficient Hypoxic Tumors Therapy.

It still remains challenging to design multifunctional therapeutic reagents for effective cancer therapy under a unique tumor microenvironment including insufficient endogenous HO and O2, low pH, and a high concentration of glutathione (GSH). In this work, a CO-based phototherapeutic system triggered by photogenerated holes, which consisted of ionic liquid (IL), the CO prodrug Mn(CO), and iridium(III) porphyrin (IrPor) modified carbonized ZIF-8-doped graphitic carbon nitride nanocomposite (IL/ZCN@Ir(CO)), was designed for cascade hypoxic tumors. Upon light irradiation, the photogenerated holes on IL/ZCN@Ir(CO) oxidize water into HO, which subsequently induces Mn(CO) to release CO.

pH-Responsive Multifunctional Nanoplatforms with Reactive Oxygen Species-Controlled Release of CO for Enhanced Oncotherapy.

Recently, various nanomaterials have drawn increasing attention for enhanced tumor therapy. However, a lack of tumor uptake and insufficient generation of cytotoxic agents have largely limited the antitumor efficacy in vivo. Herein, a multifunctional nanoplatform (IL@CPPor(CO)) was constructed with pH-responsive copper peroxide nanoparticles (CPNP) that are capable of self-supplying HO, a radical-sensitive carbonic oxide (CO) donor (Fe(CO)), photosensitizer Iridium(III) meso-tetra (-methyl-4-pyridyl)porphyrin pentachloride (IrPor), and ionic liquid (IL) for enhanced oncotherapy.

Employing bulk-heterostructure conductive polymer PFO/PFBT for the photoelectrochemical analysis of -phenylenediamine.

This study describes the implementation of conductive polymer as drop-casted film electrodes that facilitate the detection of phenol. The device configuration comprises ITO electrode modified with a film of conductive polymer heterostructures (poly(9,9-di--octylfluorene-2,7-diyl) (PFO)/poly(9,9-dioctylfluorenyl-2,7-diy)--(1,4-benzo-(2,1',3)-thiadiazole) (PFBT)). The utility of PFO/PFBT-modified electrode exhibited stable photocurrent signal under visible light irradiation.

A cell-surface-anchored DNA probe coupled with hybridization chain reaction enzyme-free dual signal amplification for sensitive electrochemical detection of the cellular microenvironment.

The cellular microenvironment plays key roles in regulating physiological processes. However, it is still a challenge to detect it with quantification. Here, a simple, biocompatible, and universal strategy based on cell surface-anchored specific DNAzymes and hybridization chain reaction enzyme-free signal amplification for cellular microenvironment electrochemical detection is presented.

A label-free dually-amplified aptamer sensor for the specific detection of amyloid-beta peptide oligomers in cerebrospinal fluids.

Amyloid-beta peptide oligomer (Aβo) is widely acknowledged to be associated with Alzheimer's disease (AD). The immediate and accurate detection of Aβo may provide the index for tracking the progress of the state of the disease, as well as some useful information for investigating the pathology of AD. In this work, based on a triple helix DNA which triggers a series of circular amplified reactions in the presence of Aβo, we designed a simple and label-free colorimetric biosensor with dually-amplified signal for the specific detection of Aβo.

Sensitive Electrochemical Sensor for Glycoprotein Detection Using a Self-Serviced-Track 3D DNA Walker and Catalytic Hairpin Assembly Enzyme-Free Signal Amplification.

Approaches for the detection of targets in the cellular microenvironment have been extensively developed. However, developing a method with sensitive and accurate analysis for noninvasive cancer diagnosis has remained challenging until now. Here, we reported a sensitive and universal electrochemical platform that integrates a self-serviced-track 3D DNA walker and catalytic hairpin assembly (CHA) triggering G-Quadruplex/Hemin DNAzyme assembly signal amplification.

Ionic liquid functionalized metal-organic framework nanowires for sensitive and real-time electrochemical monitoring of nitric oxide released from living cells.

Sensitive, selective, and real-time detection of nitric oxide (NO) is still challenging due to its rapid diffusion, short half-life, and low concentration in living systems. Herein, we synthesized well-defined ultralong metal-organic framework nanowires (MOFNWs) that were further uniformly covered with gold nanoparticle (AuNPs) and ionic liquids (ILs) and applied these NWs to detect and monitor NO released from living cells. In this system, ILs and AuNPs act as excellent catalysts for electrochemical oxidation of NO.

ROS generation strategy based on biomimetic nanosheets by self-assembly of nanozymes.

Reactive oxygen species (ROS) play an important role in physiology and have been applied in tumor therapy. However, insufficient endogenous HO and hypoxia in cancer cells can lead to limited ROS production and poor therapeutic efficacy. Herein, we develop a biomimetic nanosheet material based on the self-assembly of nanozymes that could supply HO under acidic conditions and catalyze a cascade of intracellular biochemical reactions to produce ROS under both normoxic and hypoxic conditions without any external stimuli.

In situ synthesis of ultrafine CuO on layered double hydroxide for electrochemical detection of S-nitrosothiols.

The identification and quantitation of S-nitrosothiols (RSNO) has aroused enormous levels of attention, due to RSNO have many roles in vivo. Here, we synthesized the nanocomposites of ultrafine CuO/layered double hydroxide (u-CuO/LDH) by the in situ topotactic reduction of a Cu-containing LDH with ascorbic acid under gentle conditions and applied these u-CuO/LDH to detect and monitor RSNO. Electrochemical signals of u-CuO/LDH exhibited a wide N-acetyl-S-nitrosopenicillamine detection range from 5.

Electrochemically classifying DNA structure based on the small molecule-DNA recognition.

Herein, we reported the differential binding ability of aminoglycosides to DNA structures using electrochemical method through principal component analysis (PCA) to classify different DNA secondary structures and understand the link between secondary structure and DNA conformation. In these analyses, the DNA with different secondary structure motifs: bulge, internal loop, hairpin loop and stem loop were designed. The aminoglycosides as receptors were modified on the surface of electrode.

Versatile metal-organic frameworks as a catalyst and an indicator of nitric oxide.

The imaging of nitric oxide (NO) and its donors is crucial to explore NO-related physiological and pathological processes. In this work, we demonstrate the use of Cu-based metal-organic frameworks (Cu-MOFs) as nanoprobes for NO detection and as a catalyst for the generation of NO from the biologically occurring substrate, S-nitrosothiols (RSNOs). The paramagnetic Cu in the MOFs could quench the luminescence of triphenylamine; Cu-MOFs only exhibited weak emission at 450 nm.

Porphyrin decorated CuO nanocrystals for electroanalytical detection of S-Nitrosothiols.

S-nitrosothiols (RSNO) as the potential nitric oxide (NO) storage, transfer and delivery vehicles under physiological condition have been identified as important in a number of disease states. However, a detection and quantification of RSNO method with simple and sensitive in biological media is currently lacking. A novel electrochemical sensing platform based on ionic liquid (IL) and copper porphyrin (PorCu) decorated cuprous oxide (CuO) nanocomposites was developed to detect RSNO under physiological condition.

Ultrasensitive electrochemical biosensor for protein detection based on target-triggering cascade enzyme-free signal amplification strategy.

Herein, a cost-effective, simple and sensitive electrochemical sensing platform was established based on aptamer - target recognition and target-triggering signal amplification strategy for protein detection. Due to the high affinity between the aptamer and target, the assistant DNA1 (a1) could release from a1-aptamer duplex and trigger the following DNA circuits. The strand displacement and branch migration reaction brought assistant DNA3 (a3) released.

Understanding the Performance of Metal-Organic Frameworks for Modulation of Nitric Oxide Release from S-Nitrosothiols.

S-Nitrosothiols (RSNOs) which are important intermediates in circulating reservoirs of nitric oxide (NO), transport and numerous NO signaling pathways play intricate roles in the etiology of several pathologies. However, it is still a challenge to control the release of NO from nitrosylated compounds under physiological pH. In this paper, for the first time, we report the catalytic activity and kinetic study for the modulation of NO release from RSNOs by an array of metal-organic frameworks (MOFs) (M-MOF (M'); M=Zr, Cu; and M'=Cu, Pd, no metal) under physiological conditions via time-dependent absorbance spectra.

Electrochemical biosensor based on singlet oxygen generated by molecular photosensitizers.

Here a sensing strategy with the integration of photosensitizer and electrochemical analysis was present. The photosensitizer, Zinc(II) tetraphenylporphyrin (ZnTCPP), was functionalized graphene oxide (GO) to form complex (ZnTCPP/GO) as the electrode material and generated singlet-oxygen (O) in the presence of air under light illumination. Due to the special electronic structure of O, hydroquinone (HQ) could react with O to produce electrochemically-detectable products, benzoquinone (BQ).

General Strategy to Achieve Color-Tunable Ratiometric Two-Photon Integrated Single Semiconducting Polymer Dot for Imaging Hypochlorous Acid.

It is highly desired and challenging to construct integrated (all-in-one) single semiconducting-polymer-derived dot (Pdot) without any postmodification but with desired performances for bioapplications. In this work, eight hypochlorous acid (HClO)-sensitive integrated polymers and corresponding polymer-derived Pdots are designed through molecular engineering to comparatively study their analytical performances for detecting and imaging HClO. The optimized polymers-derived Pdots are obtained through regulating donor-acceptor structure, the content of HClO-sensitive units, and the position of HClO-sensitive units in the polymer backbone.

Singlet-oxygen generated by a metal-organic framework for electrochemical biosensing.

Enzyme-based electrochemical biosensors have been widely employed for analyte detection for several years. However, for wide application, there are many challenges to overcome, such as the sensitivity of the catalytic activity, and the reproducibility and stability of enzymes. In this work, an enzyme-free sensing strategy based on two-dimensional (2D) metal-organic frameworks (MOFs) as photosensitizers and singlet-oxygen (1O2) as the oxidant has been designed via photocatalysis and electrochemical analysis.

A metal-organic framework with multienzyme activity as a biosensing platform for real-time electrochemical detection of nitric oxide and hydrogen peroxide.

A Metal-Organic Framework (MOFs) with large surface area, exposed active site, excellent catalytic performance and high chemical stability has been used as an artificial enzyme and designed for nonenzymatic electrochemical sensors. Here, a strategy of using an enhanced electrochemical sensing platform for the detection of nitic oxide (NO) and hydrogen peroxide (H2O2) was designed via a nano-metalloporphyrinic metal-organic framework (NporMOF(Fe)) as an electrode material. By taking advantage of the small size, high surface area and exposed Fe active site, the obtained NporMOF(Fe) displays excellent electrocatalytic activity toward NO and H2O2.

Engineering fluorescent semiconducting polymer nanoparticles for biological applications and beyond.

Semiconducting polymer nanoparticles (SPNs), derived from conjugated polymers (CPs), have emerged as a new class of soft fluorescent nanomaterials in recent years. Owing to the distinguished properties resulting from CPs and nanosize materials including extraordinary brightness, fast emission rate, strong photostability and outstanding biocompatibility, SPNs have shown potential for application in biosensing, bioimaging and biomedical areas. More importantly, in comparison to inorganic nanomaterials, SPNs hold more flexible modification approaches.

Nanozyme-Modified Metal-Organic Frameworks with Multienzymes Activity as Biomimetic Catalysts and Electrocatalytic Interfaces.

Many metal-organic frameworks have been designed and synthesized for biosensors because of high surface area and porosity, suitable size, and good biocompatibility. Despite recent advances, however, most of them are only used as a nanocarrier. In this work, a new artificial nanozyme was constructed on a metalloporphyrinic metal-organic framework (PMOF(Fe)), which was formed by Fe porphyrin and Zr ions.

Artificial nanozyme based on platinum nanoparticles anchored metal-organic frameworks with enhanced electrocatalytic activity for detection of telomeres activity.

This study reports a new artificial nanozyme based on ultra-small Pt nanoparticles (Pt NPs) grown on nanoscale metalloporphyrin metal organic frameworks (P-MOF(Fe)) (termed as Pt@P-MOF(Fe)) as biomimetic catalysts and redox mediator to detect the telomerase activity. In this system, the P-MOF(Fe) were used as nanocarrier and signal media. The DNA functionalized Pt@P-MOF(Fe) was as signal probe and exhibited enhanced electrochemical signal in the presence of HO, owing to the synergistic effect between P-MOF(Fe) and Pt NPs.