A comprehensive approach for quantifying source-specific ecological and health risks of potentially toxic elements in agricultural soil.

Given the pollution prevalence of potentially hazardous elements (PTEs) in agricultural soils worldwide, it is crucial to establish a comprehensive approach to accurately assess soil contamination, and quantitatively allocate sources and source-specific risks. In the study, soil contamination was assessed through environmental capacity based on the local geochemical baseline established using PTE contents of the subsoil. The sources of PTEs were quantified through positive matrix factorization (PMF) and GIS mapping.

An all-in-one smartphone-assisted ratiometric fluorescent device for visual and quantitative detection of glutathione.

The daily consumption of foods abundant in Glutathione (GSH) can be supplemented to maintain the homeostasis of GSH in human health and alleviate pathologies resulting from abnormal GSH levels. The fluorescence-based visual determination of GSH has gradually attracted the attention of researchers due to its robust performance and versatile implementation. However, the current GSH visual strategy primarily relies on variations in fluorescence intensity at a single emission wavelength, which poses challenges for naked-eye and portable readout, as well as distorted signals caused by complex matrix effects in real samples.

Biotemplated Platinum Nanozymes: Synthesis, Catalytic Regulation and Biomedical Applications.

Platinum (Pt) nanozymes with multiple intrinsic enzyme-mimicking activities have attracted extensive attention in biomedical fields due to their high catalytic activity, ease of modification, and convenient storage. However, the Pt nanozymes synthesized by the traditional method often suffer from uncontrollable morphology and poor stability under physicochemical conditions, resulting in unsatisfactory catalytic behavior in practical applications. To optimize the catalytic ability, biological templates have been introduced recently, which can guide the deposition of platinum ions on their surface to form specific morphologies and then stabilize the resulting Pt nanozymes.

Dual biomass-derived porous carbon heterogeneous functionalized mesoporous CuCoO nanocomposite combined with molecularly imprinted polymers as an electrochemical sensing platform for hypersensitive and selective determination of dimetridazole contaminants.

In this study, an original molecularly imprinted electrochemical sensor (MIECS) is prepared using layer-by-layer modification of sensitization nanomaterials (CuCoO/BPC-) coupled with molecularly imprinted polymers (MIPs) for the ultrasensitive and rapid determination of dimetridazole (DMZ) contaminants. The biomass waste of eggshell (ES) powders subtly introduced in situ in the carbonization process of psyllium husk (PSH) substantially promotes the physicochemical properties of the resulting biomass-derived porous carbon (BPC-). The large specific surface area and abundant pores provide a favourable surface for loading mesoporous CuCoO with a spinel structure.

Pt-Decorated Gold Nanoflares for High-Fidelity Phototheranostics: Reducing Side-Effects and Enhancing Cytotoxicity toward Target Cells.

Functionalized with the Au-S bond, gold nanoflares have emerged as promising candidates for theranostics. However, the presence of intracellular abundantly biothiols compromises the conventional Au-S bond, leading to the unintended release of cargoes and associated side-effects on non-target cells. Additionally, the hypoxic microenvironment in diseased regions limits treatment efficacy, especially in photodynamic therapy.

One-step, reagent-free construction of nano-enzyme as visual and reusable biosensor for oxidase substrates.

The substrates of oxidase are biologically essential substances that are closely associated with human physiological health. However, current biosensing methods suffer from tough recyclability and undesired denaturation of enzyme due to impurity interference. Herein, we have developed a visual and reusable biosensor for detecting substrate using glucose oxidase (GOx) as a model oxidase.

A Reaction-Based Ratiometric Bioluminescent Platform for Point-of-Care and Quantitative Detection Using a Smartphone.

Fluorescent probes have emerged as powerful tools for the detection of different analytes by virtue of structural tenability. However, the requirement of an excitation source largely hinders their applicability in point-of-care detection, as well as causing autofluorescence interference in complex samples. Herein, based on bioluminescence resonance energy transfer (BRET), we developed a reaction-based ratiometric bioluminescent platform, which allows the excitation-free detection of analytes.

A Polymeric Nanobeacon for Monitoring the Fluctuation of Hydrogen Polysulfides during Fertilization and Embryonic Development.

Fertilization and early embryonic development as the beginning of a new life are key biological events. Hydrogen polysulfide (H S ) plays important roles during physiological regulation, such as antioxidation-protection. However, no report has studied in situ H S fluctuation during early embryonic development because of the low abundance of H S and inadequate sensitivity of probes.

A Glucose-Powered Activatable Nanozyme Breaking pH and H O Limitations for Treating Diabetic Infections.

The peroxidase-like activity of nanozymes is promising for chemodynamic therapy by catalyzing H O into OH. However, for most nanozymes, this activity is optimal just in acidic solutions, while the pH of most physiological systems is beyond 7.0 (even >8.

Occurrence of Powdery Mildew Caused by Erysiphe buhrii on Dianthus chinensis in Inner Mongolia, China.

Dianthus chinensis is widely cultivated for ornamental and medicinal use in China (Guo et al. 2017). The plant has been used in traditional Chinese medicine for the treatment of urinary problems such as strangury and diuresis (Han et al.

Chemical composition, structure, physicochemical and functional properties of rice bran dietary fiber modified by cellulase treatment.

Rice bran dietary fiber (ERBDF) subjected to pre-water-washing and complex enzyme treatment using heat-stable α-amylase, alcalase, and glucoamylase had significantly higher (p < 0.05) proportions of cellulose, hemicellulose, lignin, and lower proportions of lipid, protein, and starch than rice bran dietary fiber subjected to complex enzyme treatment without pre-water-washing. Cellulase modification of ERBDF significantly decreased (p < 0.

A DNAzyme cascade for amplified detection of intracellular miRNA.

Inspired by the natural enzyme cascade reaction, an artificial DNAzyme cascade system is developed for the amplified detection of intracellular miR-141. The results showed that the method enormously enhanced the readout of the fluorescence signal and achieved a femtomolar detection limit.

Amplified FRET Nanoflares: An Endogenous mRNA-Powered Nanomachine for Intracellular MicroRNA Imaging.

It is of great value to detect biological molecules in live cells. However, probes for imaging low-abundance targets in live cells are limited by the one-to-one signal-triggered model. Here, we introduce the concept of the amplified FRET nanoflare, which employs high-abundance endogenous mRNA as fuel strands to amplify the detection of low abundance intracellular miRNA.

A DNA tetrahedron-based molecular computation device for the logic sensing of dual microRNAs in living cells.

Endogenous miRNA expression patterns are specific to cell type and thus offer high prediction accuracy with regard to different cell identities compared to single miRNA analysis. The "AND" logic gate can be utilized as a DNA computation device that recognizes dual-miRNA inputs through strand hybridization activated computation cascades to produce controlled outputs. To integrate all recognition and computing modules within a single structure, a DNA tetrahedron-based molecular device was constructed for the logic sensing of dual miRNAs in living cells.

Aptamer-tethered self-assembled FRET-flares for microRNA imaging in living cancer cells.

We report an aptamer-tethered, self-assembled DNA nanowire as a multivalent vehicle for the intracellular delivery of FRET flares. The FRET flares are bound to the nanowire and fluorescently labeled donors and acceptors at two ends, respectively. In the absence of targets, the flares are captured by binding with the nanowires, separating the donor and acceptor (low FRET).

Engineering DNAzyme cascade for signal transduction and amplification.

Inspired by the natural enzyme cascade reaction, a multiple DNAzyme cascade platform is engineered to imitate the intracellular process of signal transduction and signal amplification. In this design, when particular stimuli appear, an activated upstream DNAzyme will cleave a well-designed intermediary S1, releasing a downstream DNAzyme that can cleave the reporter substrate S2 to output signals. Thus, the signal is passed from the upstream DNAzyme to the downstream DNAzyme through a well-designed intermediary, accomplishing signal transduction and signal amplification.

Three-Dimensional Molecular Transfer from DNA Nanocages to Inner Gold Nanoparticle Surfaces.

It is of great interest to construct DNA-functionalized gold nanoparticles (DNA-AuNPs) with a controllable number of DNA strands and relative orientations. Herein, we describe a three-dimensional (3D) molecular transfer strategy, in which a pattern of DNA strands can be transferred from a DNA icosahedron cage (I-Cage) to the wrapped AuNP surface. The results show that DNA-AuNPs produced by this method inherit DNA pattern information encoded in the transient I-Cage template with high fidelity.

Dual-microRNA-controlled double-amplified cascaded logic DNA circuits for accurate discrimination of cell subtypes.

Accurate discrimination between different cells at the molecular level is particularly important for disease diagnosis. Endogenous RNAs are such molecular candidates for cancer cell subtype identification. But the key is that there is often low abundance of RNAs in live cells, or some RNAs are often shared by multiple types of cells.

Hairpin-fuelled catalytic nanobeacons for amplified microRNA imaging in live cells.

Direct imaging of low-abundance RNAs in live cells remains challenging because of the relatively low sensitivity of conventional molecular imaging probes. Here, we introduce hairpin-fuelled catalytic nanobeacons for microRNA (miRNA) imaging in live cells with signal amplification capacity. Compared with the conventional nanobeacons in solution, the catalytic nanobeacons could generate two orders of magnitude higher sensitivity.

Gold nanoparticle-based 2'-O-methyl modified DNA probes for breast cancerous theranostics.

MicroRNAs (miRNAs) are a class of small non-coding RNAs that regulated diverse cellular processes including differentiation, proliferation, apoptosis, metabolism and signal transduction pathways. An increasing number of data suggested that miRNA-21 could be identified as diagnostic and therapeutic biomarker for breast cancer. Meanwhile, inhibiting the function of miRNA-21, resulting in cells growth inhibition and apoptotic cells death.

Two-Color-Based Nanoflares for Multiplexed MicroRNAs Imaging in Live Cells.

MicroRNAs (miRNAs) have become an ideal biomarker candidate for early diagnosis of diseases. But various diseases involve changes in the expression of different miRNAs. Therefore, multiplexed assay of miRNAs in live cells can provide critical information for our better understanding of their roles in cells and further validating of their function in clinical diagnoses.

Live-Cell MicroRNA Imaging through MnO Nanosheet-Mediated DD-A Hybridization Chain Reaction.

Innovative techniques to visualize native microRNAs (miRNAs) in live cells can dramatically impact current research on the roles of miRNA in biology and medicine. Here, we report a novel approach for live-cell miRNA imaging using a biodegradable MnO nanosheet-mediated DD-A FRET hybridization chain reaction (HCR). The MnO nanosheets can adsorb DNA hairpin probes and deliver them into live cells.

Gold Nanoparticle Loaded Split-DNAzyme Probe for Amplified miRNA Detection in Living Cells.

A new class of intracellular nanoprobe, termed AuNP loaded split-DNAzyme probe, was developed to sense miRNA in living cells. Briefly, it consists of an AuNP and substrates hybridized with two half of split DNAzymes. In the absence of target miRNA, the split DNAzymes form an inactive DNAzyme motif with their substrate through partial paring at the end of each strand, and the fluorescence is quenched.

Gold Nanoparticle Based Hairpin-Locked-DNAzyme Probe for Amplified miRNA Imaging in Living Cells.

A new class of intracellular nanoprobe, termed AuNP-based hairpin-locked-DNAzyme probe, was developed to sense miRNA in living cells. Briefly, it consists of an AuNP and hairpin-locked-DNAzyme strands. In the absence of target miRNA, the hairpin-locked-DNAzyme strand forms a hairpin structure by intramolecular hybridization, which could inhibit the catalytic activity of DNAzyme strand and the fluorescence is quenched by the AuNP.

MnO nanosheet mediated "DD-A" FRET binary probes for sensitive detection of intracellular mRNA.

The donor donor-acceptor (DD-A) FRET model has proven to have a higher FRET efficiency than donor-acceptor acceptor (D-AA), donor-acceptor (D-A), and donor donor-acceptor acceptor (DD-AA) FRET models. The in-tube and in-cell experiments clearly demonstrate that the "DD-A" FRET binary probes can indeed increase the FRET efficiency and provide higher imaging contrast, which is about one order of magnitude higher than the ordinary "D-A" model. Furthermore, MnO nanosheets were employed to deliver these probes into living cells for intracellular TK1 mRNA detection because they can adsorb ssDNA probes, penetrate across the cell membrane and be reduced to Mn ions by intracellular GSH.