Graziana Bagni

Electrochemical biosensor evaluation of the interaction between DNA and metallo-drugs

Electrochemical techniques were used to study the interaction between a panel of antiproliferative metallo-drugs and double-stranded DNA immobilized on screen-printed electrodes as a model of the analogous interaction occurring in solution. The propensity of a given metal drug to interact with DNA was measured as a function of the decrease of guanine oxidation signal, which was detected by square wave voltammetry. Estimates of variations in experimental parameters, such as the concentration of complexes, time following dissolution (ageing time) and the presence of chloride, are provided.

DNA Biosensor Investigations in Fish Bile for Use as a Biomonitoring Tool

Abstract Polycyclic aromatic hydrocarbons (PAH) are responsible for a number of adverse effects on aquatic biota due to their persistence and potential for accumulation. The recognition and quantification of biliary PAH metabolites from exposed fish represents a valuable tool in the evaluation of warning signals indicative of exposure. In this work, an electrochemical DNA biosensor is proposed as a screening device for the rapid detection of PAH metabolites in fish bile samples. Preliminary studies were performed using the 3-hydroxy-benzo(a)pyrene as a model compound. The effect of the 3-hydroxy-benzo(a)pyrene on the surface-confined DNA was found to be linearly related to the concentration of the PAH derivative in solution. Then, the DNA biosensor was used to investigate the presence of PAH metabolites in fish bile samples. The sensor was able to clearly distinguish PAH-exposed fish bile samples from unexposed control samples. A total analysis time of 7 min was established (including electrode surface pre-treatment, dsDNA immobilization and interaction steps) and only 10 μL of diluted sample solution were needed. DNA biosensors are cost effective and sensitive; moreover, the coupling of a portable and battery-operating potentiostat with disposable carbon strips meets the requirements for in situ measurements.

As(III) Voltammetric Detection by Means of Disposable Screen‐Printed Gold Electrochemical Sensors

Abstract In this paper a disposable gold screen‐printed working electrode was tested for arsenic detection in aqueous solutions using Square Wave Anodic Stripping Voltammetry (SWASV). The dynamic range of the sensor and its response were characterised in standard As(III) solutions; particular efforts were devoted to optimize electrode surface conditioning and electrolyte solution composition. The detection limit was 2.5 µg l−1 using 60 s as deposition time. A portable battery‐operated device was used to demonstrate the possibility to use the sensor for on‐site analysis. Analysis of spiked samples was also performed.

DNA-metallodrugs interactions signaled by electrochemical biosensors: an overview.

The interaction of drugs with DNA is an important aspect in pharmacology. In recent years, many important technological advances have been made to develop new techniques to monitor biorecognition and biointeraction on solid devices. The interaction between DNA and drugs can cause chemical and conformational modifications and, thus, variation of the electrochemical properties of nucleobases. The propensity of a given compound to interact with DNA is measured as a function of the decrease of guanine oxidation signal on a DNA electrochemical biosensor. Covalent binding at N7 of guanine, electrostatic interactions, and intercalation are the events that this kind of biosensor can detect. In this context, the interaction between a panel of antitumoral Pt-, Ru-, and Ti-based metallodrugs with DNA immobilized on screen-printed electrodes has been studied. The DNA biosensors are used for semiquantitative evaluation of the analogous interaction occurring in the biological environment.

Electrochemical Device for the Rapid Detection of Genotoxic Compounds in Fish Bile Samples

Abstract The scientific goal of the present work is the development of a new molecular biomarker as a biomonitoring tool for early assessment of the biological effect of complex mixtures of pollutants (especially polycyclic aromatic hydrocarbons) and validation of the approach by comparison with standard methodologies. Hence, a DNA‐based biosensor, which is able to detect the presence of compounds with affinity for DNA to measure their effect on the guanine base, was used in this research.

Development of biomarkers in an integrated approach to environmental studies

This study was conducted in a contained environment in order to develop biomarkers and to evaluate the environmental damage after a release of two different toxic substances which are widely used in industrial production. In a simulation study performed in Tor Mancina area (near Rome, Italy), two dangerous substances (formaldehyde and bromine) were tested. Chemical and physical characterisation, nutritive and organic contents, and trace elements presence were also investigated. The contamination effects on soil functional qualities and plant nutrition were evaluated; furthermore DNA damage with short-term genotoxicity tests and DNA biosensor on polluted soils and gravitational water, was detected. The genotoxic effects were evaluated on Vicia faba seedlings by two different short-term tests: comet assay and micronuclei test. A DNA-based biosensor for the detection of genotoxic compounds in soil samples was assembled by immobilising double stranded calf thymus DNA on screen-printed electrodes. An agreement between the comet assay and the other methodologies was observed. The results showed that the nature and the concentration of the two substances result in different molecular interaction with exposed environment. Furthermore, some of the chemical physical parameters considered are applicable indicators for the evaluation of the soil?plant system pollution.

Rapid screening of alkylphenol exposure in fish bile using an enzymatic peroxidase biosensor

This article deals with the development and novel application of an amperometric peroxidase biosensor for monitoring fish exposure to petroleum-related discharges, in particular, to alkyl phenols (AP) using fish bile as the main sample material. The biosensor consisted of a screen-printed electrode coupled with peroxidase immobilized by glutaraldehyde cross-linking. The sensor was optimized with regards to factors such as immobilization procedures, substrate selectivity, and matrix effects. The biosensor was used for the analysis of fish bile samples from Atlantic cod (Gadus morhua L.) exposed in the laboratory during a 2 week period to different petroleum related compounds. The biosensor could distinguish between bile samples of fish exposed to water containing high concentrations (a mixture of C4–C7) to moderate levels (mainly C0–C5) of alkylphenols and that of the control group.