A Self-Calibrating Chemiluminescence Sensor for Rapid and Precise Antibiotic Prescribing Guidelines on Urinary Tract Infections.

Traditional antimicrobial-susceptibility testing methodologies, including the isolation and culture of bacteria from urine samples and antibiotic-susceptibility test (AST), are expensive and time-consuming. Therefore, a rapid, user-friendly phenotypic AST is urgently needed to guide treatment strategies. Several novel phenotypic AST platforms based on the physiological characteristics of bacteria obtained directly from clinical urine samples have been proposed as promising methods as rapid AST and appropriate antibiotic treatments.

6-Aza-2-Thiothymine-Capped Gold Nanoclusters as Robust Antimicrobial Nanoagents for Eradicating Multidrug-Resistant Infection.

Multidrug-resistant bacterial infections, especially those caused by multidrug-resistant () bacteria, are an ever-growing threat because of the shrinking arsenal of efficacious antibiotics. Therefore, it is urgently needed to develop a kind of novel, long-term antibacterial agent effectively overcome resistant bacteria. Herein, we present a novel designed antibacterial agent-6-Aza-2-thiothymine-capped gold nanoclusters (ATT-AuNCs), which show excellent antibacterial activity against multidrug-resistant bacteria.

Synthetic Antibacterial Quaternary Phosphorus Salts Promote Methicillin-Resistant -Infected Wound Healing.

Background: Drug-resistant microbes pose a global health concern, requiring the urgent development of effective antibacterial agents and strategies in clinical practice. Therefore, there is an urgent need to explore novel antibacterial materials to effectively eliminate bacteria. The synthesis of quaternary phosphonium salt in haloargentate systems, wherein the phosphorus atom is represented in a cationic form, is a possible strategy for the development of antibacterial materials.

Immunofluorescent-aggregation assay based on anti-Salmonella typhimurium IgG-AuNCs, for rapid detection of Salmonella typhimurium.

Sensitive and rapid detection of pathogenic bacteria plays an important role in avoiding food poisoning. However, the practical application value of conventional assays for detection of foodborne bacteria, are limited by major drawbacks; these include the laboriousness of pure culture preparation, complexity of DNA extraction for polymerase chain reaction, and low sensitivity of enzyme-linked immunosorbent assay. Herein, we designed a non-complex strategy for the sensitive, quantitative, and rapid detection of Salmonella typhimurium with high specificity, using an anti-Salmonella typhimurium IgG-AuNC-based immunofluorescent-aggregation assay.

Detection of tetanus toxoid with fluorescent tetanus human IgG-AuNC-based immunochromatography test strip.

Assays for detecting tetanus toxoid are of great significance to be applied in the research of the safety testing of tetanus vaccine. Currently, guinea pigs or mice are usually used to evaluate the toxicity in these assays. Herein, a facile and quick biomineralization process was carried out to generate tetanus human immunoglobulin G (Tet-IgG)-functionalized Au nanoclusters (Tet-IgG-AuNCs).

Decisive role of pH in synthesis of high purity fluorescent BSA-Au nanoclusters.

Various types of bovine serum albumin (BSA)-protected fluorescent gold nanoclusters (BSA-AuNCs) have been fabricated and applied in various fields. However, the conventional synthesis methods for BSA-AuNCs usually yield a low photoluminescence quantum yield (PLQY) in solution. In this study, we systematically examined the influences of incubation time, temperature, and pH on the formation process of BSA-AuNCs and then developed a novel strategy to synthesize BSA-AuNCs with PLQY (26%), far exceeding that of existing counterparts.

A Heparinase Sensor Based on a Ternary System of Hg-Heparin-Osmium Nanoparticles.

A visual assay for the detection of heparinase was developed on the basis of a ternary system of Hg-heparin-osmium nanoparticles (OsNPs). First, heparin-capped OsNPs (heparin-OsNPs) were synthesized by a facile reduction method using heparin as the protecting/stabilizing agent. The oxidase-like activity of heparin-OsNPs, however, turned out to be low, which somewhat limits their application.

Ascorbate Oxidase Mimetic Activity of Copper(II) Oxide Nanoparticles.

Although oxidase mimetic nanozymes have been widely investigated, specific biological molecules have rarely been explored as substrates, particularly in the case of ascorbate oxidase (AAO) mimetic nanozymes. Herein, we demonstrate for the first time that copper(II) oxide nanoparticles (CuO NPs) catalyze the oxidation of ascorbic acid (AA) by dissolved O (as a green oxidant) to form dehydroascorbic acid (DHAA), thus functioning as a new kind of AAO mimic. Under neutral conditions, the Michaelis-Menten constant of CuO NPs (0.

Immunoglobulin G-Encapsulated Gold Nanoclusters as Fluorescent Tags for Dot-Blot Immunoassays.

Few-atom gold nanoclusters (AuNCs) have been fabricated and used for various fields owing to their remarkable optical and photophysical features. However, the rational design for the antibody-mediated synthesis of fluorescent AuNCs for direct antigen-antibody reactions remains unexplored. In this work, immunoglobulin G (IgG)-functionalized AuNCs (IgG-AuNCs) were successfully prepared via a facile and fast biomineralization process.

Preparation of strongly fluorescent water-soluble dithiothreitol modified gold nanoclusters coated with carboxychitosan, and their application to fluorometric determination of the immunosuppressive 6-mercaptopurine.

Water-soluble and non-aggregating gold nanoclusters (AuNCs) were obtained by modification of the AuNCs with dithiothreitol (DTT) and then coating them with carboxylated chitosan. This process remarkably enhances the dispersibility of DTT-coated AuNCs in water. The resulting AuNCs, on photoexcitation at 285 nm, display strong red emission with a maximum at 650 nm and a 23% quantum yield.

An ammonia-based etchant for attaining copper nanoclusters with green fluorescence emission.

Luminescent copper nanoclusters (CuNCs) constitute a very active research topic due to their unique properties and lower cost than gold and silver NCs. In this study, we report a new, facile, and rapid top-down etching method for synthesizing luminescent CuNCs, using Cu nanoparticles (CuNPs) as the precursor and ammonia (NH3) as the etchant. The etching mechanism is systematically investigated and the optical and structural properties of the obtained CuNCs are carefully studied.

Gold Nanoparticle-Based Photoluminescent Nanoswitch Controlled by Host-Guest Recognition and Enzymatic Hydrolysis for Arginase Activity Assay.

The development of simple yet powerful methods for monitoring enzyme activity is of great significance. Herein, a facile, convenient, cost-effective, and continuous fluorescent method for the detection of arginase and its inhibitor has been reported based on a host-guest interaction-controlled and enzymatic hydrolysis-controlled luminescent nanoswitch. The fluorescence intensity of 6-aza-2-thiothymine-stabilized gold nanoparticle (ATT-AuNP) is enhanced by l-arginine, owing to the formation of a supramolecular host-guest assembly between the guanidine group of l-arginine and ATT molecules capped on the AuNP surface.

Peroxidase-like activity of nanocrystalline cobalt selenide and its application for uric acid detection.

Dendrite-like cobalt selenide nanostructures were synthesized from cobalt and selenium powder precursors by a solvothermal method in anhydrous ethylenediamine. The as-prepared nanocrystalline cobalt selenide was found to possess peroxidase-like activity that could catalyze the reaction of peroxidase substrates in the presence of HO. A spectrophotometric method for uric acid (UA) determination was developed based on the nanocrystalline cobalt selenide-catalyzed coupling reaction between -ethyl--(3-sulfopropyl)-3-methylaniline sodium salt and 4-aminoantipyrine (4-AAP) in the presence of HO.