Selective, Sensitive, and Rapid Analysis with Lateral-Flow Assays Based on Antibody-Gated Dye-Delivery Systems: The Example of Triacetone Triperoxide

[EN] Antibodygated MSNs that are loaded with a rhodamine dye and that can be used for the determination of the presence of peroxide-based explosive TATP with a lateral-flow fluorescence reader have been designed and prepared, thereby allowing for detection limits in the lower ppb range. The mechanism of the detection relies on a displacement of the antibody from the surface of the hybrid material because of highly affine antibody-TATP interactions, which release a much larger number of entrapped dye molecules from the pores than antibodies are displaced. The high selectivity of the antibody is retained in the gated material, thus allowing for a remarkable discrimination against H2O2. System…

Chromogenic Detection of Nerve Agent Mimics by Mass Transport Control at the Surface of Bifunctionalized Silica Nanoparticles

Chemical warfare (CW) agents are toxic chemicals that have been used in several terrorist attacks in recent years. Among CW species, nerve agents are probably the most dangerous; their high toxicity and facile synthesis underscores the need to detect these lethal compounds with quick, reliable procedures. Analytical methods based on enzymatic assays and physical measurements have generally been used to detect these hazards. However, these protocols usually have limitations such as low selectivity, poor portability, and a certain level of complexity. In recent years, several chromogenic and fluorogenic sensors, and reagents for the detection of nerve agents have been described. For instance,…

Selective, Highly Sensitive, and Rapid Detection of Genomic DNA by Using Gated Materials:MycoplasmaDetection

The coupling of gated-indicator delivery with highly specific biochemical recognition is an innovative strategy for the detection of DNA sequences, able to compete with classical methods which need PCR amplification, in important areas such as point-of-care diagnostics or detection of specific biological contaminations with pathogens. Such comparatively simple and cheap yet highly selective and sensitive assays hold promise for use in less-developed areas of the world.

Highly selective and sensitive chromo-fluorogenic detection of the Tetryl explosive using functional silica nanoparticles

Silica nanoparticles containing polyamines and thiol groups have been used as probes for the selective detection of Tetryl. © 2011 The Royal Society of Chemistry.

Towards chemical communication between gated nanoparticles.

The design of comparatively simple and modularly configurable artificial systems able to communicate through the exchange of chemical messengers is, to the best of our knowledge, an unexplored field. As a proof-of-concept, we present here a family of nanoparticles that have been designed to communicate with one another in a hierarchical manner. The concept involves the use of capped mesoporous silica supports in which the messenger delivered by a first type of gated nanoparticle is used to open a second type of nanoparticle, which delivers another messenger that opens a third group of gated nanoobjects.We believe that the conceptual idea that nanodevices can be designed to communicate with …

Antibody-Capped Mesoporous Nanoscopic Materials: Design of a Probe for the Selective Chromo-Fluorogenic Detection of Finasteride

[EN] The synthesis of capped mesoporous silica nanoparticles (MSN) conjugated with an antibody (AB) as a gatekeeper has been carried out in order to obtain a delivery system able to release an entrapped cargo (dye) in the presence of a target molecule (antigen) to which the conjugated antibody binds selectively. In particular, MSN loaded with rhodamine B and functionalized on the external surface with a suitable derivative of N-(t-butyl)- 3-oxo-(5a,17b)-4-aza-androst-1-ene-17-carboxamide (finasteride) have been prepared (S1). The addition of polyclonal antibodies against finasteride induced capping of the pores due to the interaction with the anchored hapten-like finasteride derivative to g…

ChemInform Abstract: Highly Enantioselective Zinc/Binol-Catalyzed Alkynylation of N-Sulfonyl Aldimines.

The Determination of Methylmercury in Real Samples Using Organically Capped Mesoporous Inorganic Materials Capable of Signal Amplification

A Rapid and Sensitive Strip-Based Quick Test for Nerve Agents Tabun, Sarin, and Soman Using BODIPY-Modified Silica Materials

Test strips that in combination with a portable fluorescence reader or digital camera can rapidly and selectively detect chemical warfare agents (CWAs) such as Tabun (GA), Sarin (GB), and Soman (GD) and their simulants in the gas phase have been developed. The strips contain spots of a hybrid indicator material consisting of a fluorescent BODIPY indicator covalently anchored into the channels of mesoporous SBA silica microparticles. The fluorescence quenching response allows the sensitive detection of CWAs in the mu g m(-3) range in a few seconds.

Highly enantioselective zinc/binol-catalyzed alkynylation of N-sulfonyl aldimines.

An aptamer-gated silica mesoporous material for thrombin detection.

An aptamer-capped mesoporous material for the selective and sensitive detection of &-thrombin in human plasma and serum has been prepared and characterised.

Enantioselective Henry reaction catalyzed with copper(II)–iminopyridine complexes

Abstract Copper complexes of chiral iminopyridines prepared from camphane-derived ketones and picolylamine catalyzed the enantioselective Henry (nitroaldol) reaction between nitromethane and a number of aromatic and aliphatic aldehydes with high yields and good enantioselectivities. Iminopyridines derived from (1 R )-(+)-camphor and (1 S )-(+)-ketopinic acid gave the best results to afford the opposite enantiomers in each case, despite the fact they have the same stereochemical pattern at the camphane skeleton. The reactions were carried out without air or moisture exclusion.

Modular iminopyridine ligands. Application to the enantioselective copper(II)-catalyzed Henry reaction

Abstract Chiral iminopyridines prepared in a modular fashion from monoterpenic (camphor-derived) ketones and pyridinylalkylamines catalyze the enantioselective Henry (nitro aldol) reaction between nitromethane and o -anisol in the presence of copper(II) acetate, with high yields and good ee (up to 86%) under straightforward experimental conditions without the need for air or moisture exclusion.

Selective opening of nanoscopic capped mesoporous inorganic materials with nerve agent simulants; an application to design chromo-fluorogenic probes.

A hybrid nanoscopic capped mesoporous material, that is selectively opened in the presence of nerve agent simulants, has been prepared and used as a probe for the chromo-fluorogenic detection of these chemicals. © 2011 The Royal Society of Chemistry.

Selektiver, hoch empfindlicher und schneller Nachweis genomischer DNA mit gesteuerten Materialien am Beispiel vonMycoplasma

[DE] Mit DNA verschlossene und mit Farbstoff beladene mesoporöse Siliciumdioxid-Nanopartikel wurden zum Nachweis von Mycoplasma bis zu einer Nachweisgrenze von ca. 70 genomischen DNA-Kopien pro mu-L in real kontaminierten Zellkulturmedien ohne die Hilfe von PCR-Techniken eingesetzt.

Über den chemischen Informationsaustausch zwischen gesteuerten Nanopartikeln

Das Design von vergleichsweise einfachen und modular konfigurierbaren k nstlichen Systemen, die ber den Austausch von chemischen Botenstoffen miteinander kommunizieren kçnnen, ist unseres Wissens ein bislang unerforschtes Gebiet. In einer grundlegenden Arbeit pr sentieren wir hier eine Serie von Nanopartikeln, die in hierarchischer Art und Weise miteinander kommunizieren kçnnen. Das Konzept beruht auf gedeckelten mesoporçsen Silikat-Tr gern, bei denen der aus einem ersten Typ von gesteuerten Nanopartikeln freigesetzte chemische Botenstoff einen zweiten Typ von gedeckelten Nanopartikeln çffnet, welche wiederum einen anderen Botenstoff freisetzen, die eine dritte Gruppe von gesteuerten Nanoob…

Determination of the chemical warfare agents Sarin, Soman and Tabun in natural waters employing fluorescent hybrid silica materials

[EN] A novel mesoporous silica material containing boron-dipyrromethene (BODIPY) moieties (I) is employed for the detection of nerve agent simulants (NASs) and the organophosphate nerve or chemical warfare agents (CWAs) Sarin (GB), Soman (GD), and Tabun (GA) in aqueous environments. The reactive BODIPY dye with an optimum positioned hydroxyl group undergoes acylation reactions with phosph(on)ate substrates, yielding a bicyclic ring. Due to aggregation of the dyes in water, the sensitivity of the free dye in solution is very low. Only after immobilization of the BODIPY moieties into the silica substrates is aggregation inhibited and a sensitive determination of the NASs diethyl cyanophosphon…

Controlled delivery using oligonucleotide-capped mesoporous silica nanoparticles.

Enhanced Efficacy and Broadening of Antibacterial Action of Drugs via the Use of Capped Mesoporous Nanoparticles

[EN] A novel nanodevice consisting of mesoporous nanoparticles loaded with vancomycin and capped with epsilon-poly-L-lysine (epsilon-PL) was prepared and its interaction with different Gram-negative bacteria studied. A remarkable improvement in the efficacy of the antimicrobial drug epsilon-PL and a broadening of the antimicrobial spectrum of vancomycin is demonstrated.