Herbicide and nutrient monitoring in surface waters and groundwater of a paddy district in northern Italy.

Italy is the leading rice producer in Europe and the second in the Mediterranean basin (after Egypt), with most of the production concentrated in a large paddy area between the Lombardy and Piedmont regions (northern Italy). In this area, irrigation of rice was traditionally carried out by wet seeding and continuous flooding; in the last fifteen years, this technique has been gradually replaced by dry seeding followed by a delayed flooding (DFL) or by an alternation of flooding and dry periods (FTI), which are economically more advantageous. This study presents the results of an extensive monitoring campaign designed and carried out in 2021 in a representative paddy district of the Lomellina area (Pavia, northern Italy) to assess the impact of the actual rice cropping strategies on surface water and groundwater quality, with particular attention to two widely used herbicides (MCPA and clomazone) and to nutrient losses (e.

Direct determination of small RNAs using a biotinylated polythiophene impedimetric genosensor.

Herein, direct determination of small RNAs is described using a functional-polymer modified genosensor. The analytical strategy adopted involves deposition by electropolymerization of biotinylated polythiophene films on the surface of miniaturized, disposable, gold screen-printed electrodes, followed by the layer-by-layer deposition of streptavidin, and then biotynilated capture probes. A small RNA (miR-221) target was determined via the impedimetric measurement of the hybridization event in a label-free and PCR-free approach.

Electrochemical, Electrochemiluminescence, and Photoelectrochemical Aptamer-Based Nanostructured Sensors for Biomarker Analysis.

Aptamer-based sensors have been intensively investigated as potential analytical tools in clinical analysis providing the desired portability, fast response, sensitivity, and specificity, in addition to lower cost and simplicity versus conventional methods. The aim of this review, without pretending to be exhaustive, is to give the readers an overview of recent important achievements about electrochemical, electrochemiluminescence, and photoelectrochemical aptasensors for the protein biomarker determination, mainly cancer related biomarkers, by selected recent publications. Special emphasis is placed on nanostructured-based aptasensors, which show a substantial improvement of the analytical performances.

Improving impedimetric nucleic acid detection by using enzyme-decorated liposomes and nanostructured screen-printed electrodes.

Sensitive impedimetric detection of miR-222, a miRNA sequence found in many lung tumors, was investigated by using gold-nanostructured disposable carbon electrodes and enzyme-decorated liposomes. The proposed method was based on the immobilization of thiolated DNA capture probes onto gold-nanostructured carbon surfaces. Afterwards, the capture probes were allowed to hybridize to the target miRNAs.

Strategies for the development of an electrochemical bioassay for TNF-alpha detection by using a non-immunoglobulin bioreceptor.

TNF-α is an inflammatory cytokine produced by the immune system. Serum TNF-α level is elevated in some pathological states such as septic shock, graft rejection, HIV infection, neurodegenerative diseases, rheumatoid arthritis and cancer. Detecting trace amount of TNF-α is, also, very important for the understanding of tumor biological processes.

Alkaline-Phosphatase-Based Nanostructure Assemblies for Electrochemical Detection of microRNAs.

Different nanoarchitectures, rich in enzyme labels, are herein investigated for signal amplification in the electrochemical detection of nucleic acids and in particular of microRNAs. Dendritic amplification, accomplished by the use of streptavidin and biotinylated alkaline phosphatase, and enzyme-decorated liposomes are used as labels to amplify the microRNA-sensing, by their association to the probe-microRNA hybrid generated onto a gold transducer. Differential pulse voltammetry and faradaic impedance spectroscopy were employed to characterize these different amplification routes.

Photoelectrochemical Biosensors for Nucleic Acid Detection.

A biosensor for detection of nucleic acids employs, as the sensing element, an oligonucleotide, with a known sequence of bases that can be used to detect specific DNA/RNA sequences through the hybridization reaction (this kind of biosensor is also called a genosensor). Many different transducers can be used in the development of a genosensor. Recently, with the emergence of novel photoelectrochemically active species and new detection schemes, photoelectrochemistry has received increasing attention in the field of biosensors.