https://zenodo.org/record/1258475/files/article.pdf

Electron transfers in chemistry and biology

Detection of chemical and biological agents plays a fundamental role in biomedical, forensic and environmental sciences1–4 as well as in anti bioterrorism applications.5–7 The development of highly sensitive, cost effective, miniature sensors is therefore in high demand which requires advanced technology coupled with fundamental knowledge in chemistry, biology and material sciences.8–13

In general, sensors feature two functional components: a recognition element to provide selective/specific binding with the target analytes and a transducer component for signaling the binding event. An efficient sensor relies heavily on these two essential components for the recognition process in terms of response time, signal to noise (S/N) ratio, selectivity and limits of detection (LOD).14,15 Therefore, designing sensors with higher efficacy depends on the development of novel materials to improve both the recognition and transduction processes. Nanomaterials feature unique physicochemical properties that can be of great utility in creating new recognition and transduction processes for chemical and biological sensors15–27 as well as improving the S/N ratio by miniaturization of the sensor elements.28

Gold nanoparticles (AuNPs) possess distinct physical and chemical attributes that make them excellent scaffolds for the fabrication of novel chemical and biological sensors (Figure 1).29–36 First, AuNPs can be synthesized in a straightforward manner and can be made highly stable. Second, they possess unique optoelectronic properties. Third, they provide high surface-to-volume ratio with excellent biocompatibility using appropriate ligands.30 Fourth, these properties of AuNPs can be readily tuned varying their size, shape and the surrounding chemical environment. For example, the binding event between recognition element and the analyte can alter physicochemical properties of transducer AuNPs, such as plasmon resonance absorption, conductivity, redox behavior, etc. that in turn can generate a detectable response signal. Finally, AuNPs offer a suitable platform for multi-functionalization with a wide range of organic or biological ligands for the selective binding and detection of small molecules and biological targets.30–32,36 Each of these attributes of AuNPs has allowed researchers to develop novel sensing strategies with improved sensitivity, stability and selectivity. In the last decade of research, the advent of AuNP as a sensory element provided us a broad spectrum of innovative approaches for the detection of metal ions, small molecules, proteins, nucleic acids, malignant cells, etc. in a rapid and efficient manner.37



Figure 1

Physical properties of AuNPs and schematic illustration of an AuNP-based detection system.



In this current review, we have highlighted the several synthetic routes and properties of AuNPs that make them excellent probes for different sensing strategies. Furthermore, we will discuss various sensing strategies and major advances in the last two decades of research utilizing AuNPs in the detection of variety of target analytes including metal ions, organic molecules, proteins, nucleic acids, and microorganisms.

/pdf/gold-nanoparticles-in-chemical-and-biological-sensing-5e2qojkdzn.pdf

Gold nanoparticles in chemical and biological sensing.

The science of the total environment

Recent developments in polysaccharide-based materials used as adsorbents in wastewater treatment

Direct And Mediated Anodic Oxidation of Organic Pollutants

An on-line pre-concentration system for electrothermal atomic absorption spectrometry was developed. A miniature silica C18 column was inserted at the tip of the autosampler arm. A modification of the tubing line of the autosampler allowed either the flow of the sample through the column or the operation of the autosampler in the normal mode. The retention of the metal ions in the form of complexes on the microcolumn was achieved by using pyrrolidin-l-yl dithioformate as the complexing agent; acetonitrile was then used for the elution. The direct injection of the eluate into the graphite furnace gave high pre-concentration factors, ranging between 20 and 225, which are sufficient for the determination of Cd, Pb, Cu, Ni, Co and Fe in Antarctic sea-water. The blank level was very low and the detection limits ranged from 0.4 ng l–1(Cd) to 25 ng l–1(Fe).

Determination of ultra-trace levels of metal ions in sea-water with on-line pre-concentration and electrothermal atomic absorption spectrometry

https://aperto.unito.it/bitstream/2318/76071/2/OA_As%20in%20contaminated%20soil_Giacomino%20et%20al.pdf

An approach for arsenic in a contaminated soil: speciation, fractionation, extraction and effluent decontamination.

L'hydroxy-8 quinoleine et l'acide hydroxy-8 quinoleinesulfonique-5 ont ete absorbees sur une resine Amberlite XAD-2 et sur une resine echangeuse d'anion pour l'absorption et l'enrichissement de traces d'ions metalliques Les ions etudies sont les suivants: Ca(II), Cd(II), Cu(II), Mg(II), Mn(II), Ni(II), Pb(II) et Zn(II) L'absorption et les quantites recuperees ont ete determinees par spectrometrie d'emission ICP Les resines d'absorption ainsi preparees ont ete utilisees pour l'enrichissement d'echantillons de l'environnement

Edoardo Mentasti

Papers

Determination of ultra-trace levels of metal ions in sea-water with on-line pre-concentration and electrothermal atomic absorption spectrometry

An approach for arsenic in a contaminated soil: speciation, fractionation, extraction and effluent decontamination.

Immobilized 8-oxine units on different solid sorbents for the uptake of metal traces

Determination and speciation of metals by liquid chromatography

Geochemical characterisation of Antarctic soils and lacustrine sediments from Terra Nova Bay