Novel immunosensor for nonylphenol (NP) determination has been developed by immobilization of specific antibodies together with horseradish peroxidase on the surface of carbon screen-printed electrode. The signal of the immunosensor is generated by the involvement of NP accumulated in the peroxidase oxidation of mediator (Methylene Blue, hydroquinone or iodide). This results in the increase of the signal recorded by linear-sweep voltammetry. The sensitivity of the detection depends on the nature of mediator, its concentration and incubation period. Cross-selectivity of the response toward readily oxidized phenolic compounds has been determined. The immunosensor developed makes it possible to detect from 20 microgL(-1) to 44 mgL(-1) of NP with detection limit 10 microgL(-1) of NP.
[Show abstract][Hide abstract] ABSTRACT: On-line solid phase extraction (SPE) coupled to liquid chromatography-mass spectrometry (LC-MS) and biosensors are advanced technologies that have found increasing application in the analysis of environmental contaminants although their application to the determination of emerging contaminants (previously unknown or unrecognized pollutants) has been still limited. This review covers the most recent advances occurred in the areas of on-line SPE-LC-MS and biosensors, discusses and compares the main strengths and limitations of the two approaches, and examines their most relevant applications to the analysis of emerging contaminants in environmental waters. So far, the on-line configuration most frequently used has been SPE coupled to liquid chromatography-(tandem) mass spectrometry. Sorbents used for on-line SPE have included both traditional (alkyl-bonded silicas and polymers) and novel (restricted access materials (RAMs), molecularly imprinted synthetic polymers (MIPs), and immobilized receptors or antibodies (immunosorbents) materials. The biosensor technologies most frequently applied have been based on the use of antibodies and, to a lesser extent, enzymes, bacteria, receptors and DNA as recognition elements, and the use of optical and electrochemical transducing elements. Emerging contaminants investigated by means of these two techniques have included pharmaceuticals, endocrine disrupting compounds such as estrogens, alkylphenols and bisphenol A, pesticides transformation products, disinfection by-products, and bacterial toxins and mycotoxins, among others. Both techniques offer advantageous, and frequently comparable, features such as high sensitivity and selectivity, minimum sample manipulation, and automation. Biosensors are, in addition, relatively cheap and fast, which make them ideally suited for routine testing and screening of samples; however, in most cases, they can not compete yet with on-line SPE procedures in terms of accuracy, reproducibility, reliability (confirmation) of results, and capacity for multi-analyte determination.
Journal of Chromatography A 07/2007; 1152(1-2):97-115. DOI:10.1016/j.chroma.2007.01.046 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The development of analytical methods that respond to the growing need to perform rapid ‘in situ’ analyses shows disposable screen-printed electrodes (SPEs) as an alternative to the traditional electrodes. This review presents recent developments in the electrochemical application of disposable screen-printed sensors, according to the types of materials used to modify the working electrode. Therefore, unmodified SPE, film-modified SPE, enzyme-modified SPE and antigen/antibody-modified SPE are described. Applications are included where available.
[Show abstract][Hide abstract] ABSTRACT: The principles used for the development of electrochemical biosensors based on horseradish peroxidase are described. Peroxidase
is the enzyme which catalyses the oxidation of a variety of organic molecules in the presence of hydrogen peroxide. The features
of this enzyme are high catalytic activity and low specificity towards second substrate as well. Horseradish peroxidase may
be used as a component of active part of biosensors for the detection of hydrogen peroxide and other compounds when peroxidase
is co-immobilized together with other oxidases. Also horseradish peroxidase may be used as a component of detecting system
for the biosensors based on biological recognition using specific antibodies, receptors, nucleic acids. The examples of the
bio-, immuno-, DNA-sensors developed for the determination of various biologically active compounds are given.
Russian Journal of General Chemistry 01/2008; 78(12):2482-2488. DOI:10.1134/S1070363208120293 · 0.48 Impact Factor
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