Responsive luminescent silver-based metal-organic frameworks for highly sensitive and selective detection of hydrogen sulfide in biological system via a self-assembled headspace separation device.

As a highly toxic gas pollutant and also an endogenous gaseous signaling molecule existing in a variety of physiological processes, the rapid and accurate in-field detection of hydrogen sulfide is of great concern. Nevertheless, two drawbacks as for the optical probes for HS detection, taking about a long time to reach the optical signal balance or the low selectivity, always exist. Herein, by using a highly photoluminescent and HS-stimuli responsive silver-based metal-organic frameworks (MOFs): Ag-BDC (BDC = 1, 4-benzene dicarboxylate), we demonstrated that the luminescence intensity of Ag-BDC MOFs was inversely proportional to the concentration of HS due to the Ag-S coordination and the obstruction of ligand-to-metal charge transfer (LMCT) transition process, and there was a quick response time of below 3.

A portable test strip fabricated of luminescent lanthanide-functionalized metal-organic frameworks for rapid and visual detection of tetracycline antibiotics.

Tetracycline antibiotics (TCs) are commonly used antibiotics in the treatment of infections, but their overuse has a negative impact on human health and ecosystems. Thus, the development of a facile and on-site visualization method for TC detection is necessary. Here, we propose the potential of using lanthanide-functionalized metal-organic framework (MOF) composites (Ag/Tb@UiO-66-(COOH), ATUC) as a probe for the rapid detection of tetracycline (TC), chlortetracycline (CTC), oxytetracycline (OTC), and doxycycline (DOX) residues, in which UiO-66-(COOH) (UC) could be utilized to provide an interaction microenvironment, Tb as recognition units and Ag as a fluorescence enhancer.

Point-of-care testing of melamine gas pressure readout using polythymine-coated Au@Pt nanoparticles through specific triple hydrogen-bonding recognition.

The adsorption of single-stranded oligonucleotides (ssDNA) on gold nanoparticles (AuNPs) could stabilize AuNPs against aggregation even at high salt concentrations, and similar phenomena have also been observed on Au core/Pt shell nanoparticles (Au@PtNPs). Inspired by the knowledge that thymine can easily recognize melamine by forming triple H-bonds in aqueous medium, in this contribution, using polythymine-coated Au@PtNPs as the probe, we demonstrated that the responsive aggregation of polyT stabilized Au@PtNPs could occur and therefore result in the significant inhibition of the catalysed gas-generation reaction, the decomposition of HO to HO and O catalyzed by Au@PtNPs. Consequently, a pressure-based signaling strategy was developed for highly sensitive and specific melamine detection not only in laboratory but also in point-of-care (POC) settings, and the correlation between the pressure change (Δ) signal and the melamine concentration was found to be linear from 0.

Facile synthesis of highly luminescent rod-like terbium-based metal-organic frameworks for sensitive detection of olaquindox.

Olaquindox (OLA), a chemically synthesized antibacterial growth promoter, despite being strictly controlled, is illegally used in feed to improve feed conversion efficiency and increase the rate of weight gain for animals. However, it has become clear that OLA has toxic effects on human beings the transmission of OLA through the food chain. Here, by employing terbium nitrate to provide metal ions and benzene-1,3,5-tricarboxylic acid (HBTC) as an organic ligand, a simple, rapid, and easy scale-up synthetic method was presented for the fabrication of water-stable and highly luminescent rod-like metal-organic frameworks (Tb-BTC MOFs).

A gas pressure and colorimetric signal dual-mode strategy for sensitive detection of spermine using ssDNA-coated Au@Pt nanoparticles as the probe.

The naturally occurring spermine (Spm), as one of the many cationic polyamines, plays a key role in biological processes and is involved in a variety of diseases. The very similar structures among biogenic polyamines present a major challenge to achieve discriminative testing among them. In this contribution, using arbitrary ssDNA-coated Au@PtNPs as the probe, we demonstrated that a dual-mode strategy via a gas pressure and colorimetric signal readout can be used for the sensitive and specific detection of Spm, due to the target-responsive aggregation of the Au@PtNPs leading to the inhibition of the catalyzed gas-generation reaction and the colorimetric change of the Au@PtNP solution.

A cost-effective and rapid quantitative test of polymyxin B sulphate with a simple and portable pressure meter readout.

Any signals, if their intensities have a simple functional relationship with analyte concentration, can be applied for analytical purposes. Among them, pressure measurement as a signalling technique has been extensively utilized to develop portable and quantitative bioanalysis, with the advantages of highly sensitive detection of a variety of biomedical targets. In this contribution, it was found that polymyxin B sulphate (PMB) could significantly inhibit the catalytic ability of platinum nanoparticles (PtNPs) prepared in different protocols in the H2O2 breakdown reaction.

pH-Dependent photoluminescence "switch-on" nanosensors composed of silver nanoparticles and nitrogen and sulphur co-doped carbon dots for discriminative detection of biothiols.

Very close structure and property similarities among biothiols, such as glutathione (GSH), cysteine (Cys), and homocysteine (Hcy), present a major challenge to achieve their discriminative detection. In this contribution, a nanomaterial surface energy transfer (NSET) system was established to discriminate GSH from Cys and Hcy with the photoluminescence (PL) "switch-on" response. The nanosensor was constructed using nitrogen and sulphur co-doped carbon dots (N,S-CDs) and silver nanoparticles (AgNPs) through assembling an energy transfer-based quenching system, featuring the pH-promoted distinct PL "switch-on" response.

Probing the Microenvironments in a Polymer-Wrapped Core-Shell Nanoassembly Using Pyrene Chromophores.

The local environments within an amphiphilic polymer shell wrapped around lanthanide-doped upconverting nanoparticles were probed using steady-state and time-resolved fluorescence spectroscopy techniques. Emission lifetime measurements of pyrene chromophores trapped within the polymer shell reveal that there are at least two environments, where the organic pyrene molecules are encapsulated in hydrophobic environments that have lower polarity than in water. The migration of pyrene chromophores from their initial location to another location was also observed, demonstrating that the polymeric shell provides both hydrophobicity and mobility for entrapped molecules.

Point-of-Care Testing of Pathogenic Bacteria at the Single-Colony Level via Gas Pressure Readout Using Aptamer-Coated Magnetic CuFeO and Vancomycin-Capped Platinum Nanoparticles.

Pressure measurements are performed everyday with simple devices, and in the field of analytical chemistry the pressure-based signaling strategy offers two important advantages, signal amplification and particular applicability in point-of-care settings. Herein, by using vancomycin (Van)-functionalized platinum nanoparticles (PtNPs@Van) and aptamer-coated magnetic CuFeO nanoprobes dual-recognition units integrated with a catalyzed breakdown of HO for O generation, we demonstrated that gas pressure can be used as a readout means for highly sensitive pathogenic bacteria identification and quantification. Using Staphylococcus aureus ( S.

A photoluminescence "switch-on" nanosensor composed of nitrogen and sulphur co-doped carbon dots and gold nanoparticles for discriminative detection of glutathione.

Biological thiols play a key role in biological processes and are involved in a variety of diseases. The discriminative detection of biological thiols is still challenging. In this contribution, a platform, an energy transfer-based quenching system composed of nitrogen and sulphur co-doped carbon dots (N, S-CDs) and gold nanoparticles (AuNPs), was established to discriminate glutathione (GSH) from other competitive biothiols including cysteine (Cys) and homocysteine (Hcy) based on a photoluminescence (PL) "switch-on" signal readout.

Optically Active Ultrafine Au-Ag Alloy Nanoparticles Used for Colorimetric Chiral Recognition and Circular Dichroism Sensing of Enantiomers.

Despite a significant surge in the number of investigations into chirality at the nanoscale, especially thiolated chiral molecules capping gold clusters, only limited knowledge is currently available to elaborate the alloying effect on chiroptical behavior of bimetallic nanoparticles (NPs). Also, few successful cases as to the efforts toward the development of chirality-dependent applications on the optically active nanomaterial have been made. Herein, as a positive test case for chiral alloy nanoparticle synthesis, the stable and large chiroptical ultrafine Au-Ag alloy NPs were prepared by reduction of different molar fractions of HAuCl and AgNO with NaBH in the presence of d/l-penicillamine (d/l-Pen).

Optically active red-emitting Cu nanoclusters originating from complexation and redox reaction between copper(ii) and d/l-penicillamine.

Despite a significant surge in the number of investigations into both optically active Au and Ag nanostructures, there is currently only limited knowledge about optically active Cu nanoclusters (CuNCs) and their potential applications. Here, we have succeeded in preparing a pair of optically active red-emitting CuNCs on the basis of complexation and redox reaction between copper(ii) and penicillamine (Pen) enantiomers, in which Pen serves as both a reducing agent and a stabilizing ligand. Significantly, the CuNCs feature unique aggregation induced emission (AIE) characteristics and therefore can serve as pH stimuli-responsive functional materials.

Allelopathic effects of Ailanthus altissima extracts on Microcystis aeruginosa growth, physiological changes and microcystins release.

The use of allelochemicals has been proved an environmentally friendly and promising method to control harmful algal blooms. This study was conducted to explore the application potential of Ailanthus altissima (A. altissima) extracts in Microcystis aeruginosa (M.

Porphyrin-loaded liposomes and graphene oxide used for the membrane pore-forming protein assay and inhibitor screening.

The interaction of planar aromatic molecules with the graphene oxide (GO) sheets is often marked by the fluorescence quenching of the former. Here, the α,β,γ,δ-tetrakis[4-(trimethylammoniumyl)phenyl]porphyrin (TAPP) molecules and the GO, corresponding to the energy donor and the acceptor respectively, are initially separated by encapsulating the TAPP molecules within the liposomes, to obstruct the formation of the self-assembled energy transfer-based quenching system. Upon disruption of the liposome membranes by the PLA2 or the α-toxin, the encapsulated TAPP molecules are released and subsequently result in significant fluorescence changes.

New colorimetric and fluorometric sensing strategy based on the anisotropic growth of histidine-mediated synthesis of gold nanoclusters for iodide-specific detection.

Iodide, as a biologically important anion, it remains a worthwhile yet challenging undertaking to find a sensitive and specific approach to provide a technically simple iodide detection. In this article, it was found that no other ions than iodide-induced anisotropic growth of gold nanocrystals (AuNCs) originated from a small molecule, histidine-mediated synthesis of AuNCs, were observed. Simultaneously, it is accompanied by the fluorescence quenching of AuNCs and the naked-eye visible color change.

Does phenoloxidase contributed to the resistance? Selection with butane-fipronil enhanced its activities from diamondback moths.

Using microtitration method, the relationship between Phenoloxidase activity and the resistance of the diamondback moth Plutella xylostella (Linnaeus) to the novel insecticide butane-fipronil was determined in vitro. After selection of the tenth-generation by butane-fipronil, the resistance of the fourth instar larvae was increased 83.80-fold as compared to the susceptible strain.

Increased inflammatory factors activity in model rats with experimental autoimmune prostatitis.

Male rats were immunized with prostate tissue homogenate supernate (PTHS) of male rats with complete Freund's adjuvant (CFA) intra dermal in the multiple points and simultaneously immunized with 0.5 ml Pertussis-Diphtheria-Tetanus (PDT) vaccine intra peritonea on 0 and 30th day. At the 45th day after first immunization, animals were sacrificed and a series of examinations such as HE stain, assay of TNF-alpha by ELISA and assay of inducible nitric oxide synthase (iNOS) mRNA by in-situ hybridization (ISH) were taken.

[Morphological and molecular biological peculiarities of the experimental autoimmune prostatitis rat model].

Objective: To observe the morphological and molecular biological peculiarities of the experimental autoimmune prostatitis (EAP) rat model made by SC purified prostate protein twice with immune adjuvant.

Methods: Male rats were intradermally immunized with a saline extract of male rat prostate glands (RPG) in Freund's complete adjuvant (FCA) and Pertussis-Diphtheria-Tetanus vaccine 0.5 ml i.