A multiplexed immunochemical microarray for the determination of cardiovascular disease biomarkers.

A fluorescence antibody microarray has been developed for the determination of relevant cardiovascular disease biomarkers for the analysis of human plasma samples. Recording characteristic protein molecular fingerprints to assess individual's states of health could allow diagnosis to go beyond the simple identification of the disease, providing information on its stage or prognosis. Precisely, cardiovascular diseases (CVDs) are complex disorders which involve different degenerative processes encompassing a collection of biomarkers related to disease progression or stage.

Engineering a Point-of-Care Paper-Microfluidic Electrochemical Device Applied to the Multiplexed Quantitative Detection of Biomarkers in Sputum.

Health initiatives worldwide demand affordable point-of-care devices to aid in the reduction of morbidity and mortality rates of high-incidence infectious and noncommunicable diseases. However, the production of robust and reliable easy-to-use diagnostic platforms showing the ability to quantitatively measure several biomarkers in physiological fluids and that could in turn be decentralized to reach any relevant environment remains a challenge. Here, we show the particular combination of paper-microfluidic technology, electrochemical transduction, and magnetic nanoparticle-based immunoassay approaches to produce a unique, compact, and easily deployable multiplex device to simultaneously measure interleukin-8, tumor necrosis factor-α, and myeloperoxidase biomarkers in sputum, developed with the aim of facilitating the timely detection of acute exacerbations of chronic obstructive pulmonary disease.

Compact Microfluidic Platform with LED Light-Actuated Valves for Enzyme-Linked Immunosorbent Assay Automation.

Lab-on-a-chip devices incorporating valves and pumps can perform complex assays involving multiple reagents. However, the instruments used to drive these chips are complex and bulky. In this article, a new wax valve design that uses light from a light emitting diode (LED) for both opening and closing is reported.

Direct Quantitative Immunochemical Analysis of Autoinducer Peptide IV for Diagnosing and Stratifying Infections.

An immunochemical strategy to detect and quantify AIP-IV, the quorum sensing (QS) signaling molecule produced by type IV, is reported here for the first time. Theoretical calculations and molecular modeling studies have assisted on the design and synthesis of a suitable peptide hapten (AIPIVS), allowing to obtain high avidity and specific antibodies toward this peptide despite its low molecular weight. The ELISA developed achieves an IC value of 2.

Diagnosis and Stratification of Infected Patients by Immunochemical Quantitative Determination of Pyocyanin From Clinical Bacterial Isolates.

The development of a highly sensitive, specific, and reliable immunochemical assay to detect pyocyanin (PYO), one of the most important virulence factors (VFs) of , is here reported. The assay uses a high-affinity monoclonal antibody (mAb; C.9.

Bacteria Detection at a Single-Cell Level through a Cyanotype-Based Photochemical Reaction.

The detection of living organisms at very low concentrations is necessary for the early diagnosis of bacterial infections, but it is still challenging as there is a need for signal amplification. Cell culture, nucleic acid amplification, or nanostructure-based signal enhancement are the most common amplification methods, relying on long, tedious, complex, or expensive procedures. Here, we present a cyanotype-based photochemical amplification reaction enabling the detection of low bacterial concentrations up to a single-cell level.

Assessment of analytical methods to determine pyrethroids content of bednets.

Objective: To present and evaluate simple, cost-effective tests to determine the amount of insecticide on treated materials.

Methods: We developed and evaluated a competitive immunoassay on two different platforms: a label-free impedimetric biosensor (EIS biosensor) and a lateral flow. Both approaches were validated by gas chromatography (GC) and ELISA, gold standards for analytical methods and immunoassays, respectively.

Electrochemical detection of fluoroquinolone antibiotics in milk using a magneto immunosensor.

An amperometric magneto-immunosensor (AMIS) for the detection of residues of fluoroquinolone antibiotics in milk samples is described for the first time. The immunosensor presented combines magnetic beads biomodified with an antibody with a broad recognition profile of fluoroquinolones, a haptenized enzyme and a magnetic graphite-epoxy composite (m-GEC) electrode. After the immunochemical reaction with specific enzyme tracer, the antibody biomodified magnetic beads are easily captured by an electrode made of graphite-epoxy composite containing a magnet, which also acts as transducer for the electrochemical detection.

Design and fabrication of a COP-based microfluidic chip: chronoamperometric detection of Troponin T.

This work demonstrates the design and fabrication of an all cyclo-olefin polymer based microfluidic device capable of capturing magnetic beads and performing electrochemical detection in a series of gold electrodes. The size of chip is of a microscope slide and features six independent measuring cells for multianalyte detection purposes. The aim of this work is to show that rapid prototyping techniques can be instrumental in the development of novel bioassays, particularly in clinical diagnosis applications.

Validation of an enzyme-linked immunosorbent assay for detecting sulfonamides in feed resources.

An enzyme-linked immunosorbent assay (ELISA) to screen sulfadiazine and sulfamethazine residues in feeds has been developed and validated according to Commission Decision 2002/657/EC criteria. Sulfonamides are easily extracted with a 95:5 acetonitrile/water mixture, obtaining recoveries between 80 and 100%. Accuracy, precision, selectivity, robustness, limit of detection (LOD), and detection capability (CCbeta) of the assay have been assessed during the validation process.

Electronic anabolic steroid recognition with carbon nanotube field-effect transistors.

A proof of concept of the electronic detection of two anabolic steroids, stanozolol (Stz) and methylboldenone (MB), was carried out using two specific antibodies and arrays of carbon nanotube field-effect transistors (CNTFETs). Antibodies specific for Stz and MB were prepared and immobilized on the carbon nanotubes (CNTs) using two different approaches: direct noncovalent bonding of antibodies to the devices and bonding the antibodies covalently to a polymer previously attached to the CNTFETs. The results indicated that CNTFETs bonded to specific antibodies covalently or noncovalently are able to detect the presence of steroids.

Competitive multi-immunosensing of pesticides based on the particle manipulation with negative dielectrophoresis.

In this work, we have applied particle manipulation based on negative dielectrophoresis (n-DEP) to develop rapid and separation-free immunosensing systems. Two widely used pesticides, atrazine and bromopropylate, were used as target molecules to demonstrate competitive immunosensing based on the rapid manipulation of microparticles. A suspension of the fluorescence microparticles modified with a specific antibody was injected into the n-DEP device consisting of the interdigitated microarray (IDA) electrode and indium-tin-oxide (ITO) substrate immobilized by protein conjugation with antigen.

Non-specific adsorption of streptavidin on single walled carbon nanotubes.

We report the semi quantitative determination of the non specific adsorption of streptavidin onto raw and functionalized single walled nanotubes (SWNTs) using different approaches. SWNTs were covalently functionalized with carboxylated groups, amine groups and polyethylene glycol (PEG), and non-covalently functionalized with polyethylene glycol, Pluronic F-127 and Tween20. SWNTs covalent functionalization has been carried out through oxidation and acyl chloride formation.

Biosensors for environmental monitoring A global perspective.

The intention of this article is to reflect the advances and describe the trends on biosensors for environmental applications. Biosensors are useful analytical tools for environmental monitoring, capable of providing results in real time, simple to use, portable and cost-effective. Some examples of biosensors in advanced stage of development, which have been applied to real samples, as well as of commercial devices, are given.

Three-dimensional interdigitated electrode array as a transducer for label-free biosensors.

A new transducer for biosensor applications has been developed based on a three-dimensional interdigitated electrode array (IDEA) with electrode digits separated by an insulating barrier. Binding of molecules to a chemically modified surface of the transducer induces important changes in conductivity between the electrodes. Three-dimensional sensor shows considerable improvement compared with a standard planar IDEA design.

Preparation of antibodies and development of a sensitive immunoassay with fluorescence detection for triazine herbicides.

Specific polyclonal antibodies against s-triazine herbicides were obtained by preparing immunogens coupling home-synthesized haptens derivatives of simazine (6-chloro-N-ethyl-N'-ethyl-1,3,5-triazine-2,4-diamine) to lysine groups of hemocyanin from keyhole limpets and bovine serum albumin carrier proteins. Three highly sensitive rabbit antisera were obtained and evaluated with a battery of six enzyme tracers derived from triazine structures in an optimized ELISA format. The antiserum As8 and the HRP-2f tracer, which yield the best assay sensitivity for simazine (detection limit 0.

Evaluation of a newly developed enzyme-linked immunosorbent assay for determination of linear alkyl benzenesulfonates in wastewater treatment plants.

A recently developed enzyme-linked immunosorbent assay (ELISA) for the determination of linear alkyl benzenesulfonates (LAS) and long chain sulfophenyl carboxylates (SPCs) has been evaluated for its application in wastewater control analysis. This ELISA based on the use of polyclonal antibodies in an indirect format shows an IC50 of 28.1 +/- 3.

Biosensors for environmental monitoring of endocrine disruptors: a review article.

This article provides an overview of the applications of biosensors in analysis and monitoring of endocrine-disrupting compounds (EDCs) in the environment. Special attention is devoted to the various types of physical-chemical signal transduction elements, biological mechanisms employed as sensing elements and techniques used for immobilisation of the bioreceptor molecules on the transducer surface. Two different classes of biosensors for EDCs are considered: biosensors that measure endocrine-disrupting effects, and biosensors that respond to the presence of a specific substance (or group of substances) based on the specific recognition of a biomolecule.

Determination of Irgarol 1051 in Western Mediterranean sediments. Development and application of supercritical fluid extraction-immunoaffinity chromatography procedure.

A supercritical fluid extraction (SFE) procedure for Irgarol 1051 (i.e. 2-(tert-butylamino)-4-(cyclopropylamino)-6-(methylthio)-1,3,5-triazine) determination in marine sediments, which minimises the solvent usage, is developed and compared to a conventional extraction technique (i.