Morena Silvestrini

Bio: Morena Silvestrini is an academic researcher from Ca' Foscari University of Venice. The author has contributed to research in topics: Photoresist & Biosensor. The author has an hindex of 7, co-authored 12 publications receiving 163 citations.

A Sensitive Electrochemiluminescence Immunosensor for Celiac Disease Diagnosis Based on Nanoelectrode Ensembles

Abstract: We report here the design of a novel immunosensor and its application for celiac disease diagnosis, based on an electrogenerated chemiluminescence (ECL) readout, using membrane-templated gold nanoelectrode ensembles (NEEs) as a detection platform. An original sensing strategy is presented by segregating spatially the initial electrochemical reaction and the location of the immobilized biomolecules where ECL is finally emitted. The recognition scaffold is the following: tissue transglutaminase (tTG) is immobilized as a capturing agent on the polycarbonate (PC) surface of the track-etched templating membrane. It captures the target tissue transglutaminase antibody (anti-tTG), and finally allows the immobilization of a streptavidin-modified ruthenium-based ECL label via reaction with a suitable biotinylated secondary antibody. The application of an oxidizing potential in a tri-n-propylamine (TPrA) solution generates an intense and sharp ECL signal, suitable for analytical purposes. Voltammetric and ECL analy...

Detection of DNA Hybridization by Methylene Blue Electrochemistry at Activated Nanoelectrode Ensembles.

Abstract: Nanoelectrode ensembles (NEEs) obtained by electroless gold deposition in track-etched poly-carbonate (PC) membranes are functionalized and applied for DNA hybridization detection, using methylene blue (MB) as electroactive probe. To this aim, an amine terminated (ss)DNA probe is immobilized on the PC surface of the NEE by reaction via carbodiimide and N-hydroxysulfosuccinimide. In order to increase the number of carboxylic groups present on PC and suitable for the functionalization, the surface of NEEs is oxidized with potassium permanganate. The presence of carboxylic functionalities is verified by spectrochemical titration with thionin acetate (THA) and the effect of the activation treatment on the electrode performances is evaluated by cyclic voltammetry (CV). After activation and functionalization with the probes, the NEE-based sensor is hybridized with complementary target sequences. The effect of the functionalization of the NEEs both with the (ss)DNA probe alone and after hybridization with the target, is studied by measuring the changes in the MB reduction signal by square wave voltammetry (SWV), after incubation in a suitable MB solution, rinsing and transfer to the measurement cell. It was observed that this peak signal decreases significantly after hybridization of the probe with the complementary target. Experimental evidences suggest that the interaction between MB and the guanines of (ss)DNA and (ds)DNA is at the basis of the development of the here observed analytical signal. The proposed approach allows the easy preparation and testing of NEE-based sensors for the electrochemical DNA hybridization detection.

Nanoelectrode ensembles for the direct voltammetric determination of trace iodide in water.

Abstract: Procedures for the preparation and characterisation of ensembles of gold nanodisk electrodes (NEE) of 30 nm diameter are presented, in particular focusing on improvements in the signal/background current ratios and detection limits with respect to the electrochemical oxidation of iodide and its analytical determination in water samples. At NEEs iodide undergoes a quasi-reversible diffusion controlled oxidation with a slight shift in E 1/2 values and slightly higher peak to peak separation with respect to conventional gold disk electrodes. The double layer charging current at the NEE is significantly lower than at conventional electrodes so that the detection limit (DL) by cyclic voltammetry with NEEs in tap water is significantly lower than DL at the Au-disk millimetre-sized electrode (DL 0.3 µM at NEE vs. 4 µM for Au-disk). Finally, it is shown that NEEs in combination with square wave voltammetry can be applied for the direct determination of iodide in water samples from the lagoon of Venice, with a det...

Nanomaterials based electrochemical sensors for biomedical applications

Abstract: A growing variety of sensors have increasingly significant impacts on everyday life. Key issues to take into consideration toward the integration of biosensing platforms include the demand for minimal costs and the potential for real time monitoring, particularly for point-of-care applications where simplicity must also be considered. In light of these developmental factors, electrochemical approaches are the most promising candidate technologies due to their simplicity, high sensitivity and specificity. The primary focus of this review is to highlight the utility of nanomaterials, which are currently being studied for in vivo and in vitro medical applications as robust and tunable diagnostic and therapeutic platforms. Highly sensitive and precise nanomaterials based biosensors have opened up the possibility of creating novel technologies for the early-stage detection and diagnosis of disease related biomarkers. The attractive properties of nanomaterials have paved the way for the fabrication of a wide range of electrochemical sensors that exhibit improved analytical capacities. This review aims to provide insights into nanomaterials based electrochemical sensors and to illustrate their benefits in various key biomedical applications. This emerging discipline, at the interface of chemistry and the life sciences, offers a broad palette of opportunities for researchers with interests that encompass nanomaterials synthesis, supramolecular chemistry, controllable drug delivery and targeted theranostics in biology and medicine.

Recent Advances in Electrochemiluminescence Analysis.

Abstract: ■ CONTENTS Novel ECL Systems 358 Novel Organic Luminophores 358 Novel Inorganic Luminophores 359 Novel Nanomaterial System 360 Detection Methodologies and Signaling Amplification Strategies 361 General Detection Methodologies 361 Novel Signal Amplification Strategies 361 ECL Applications 362 Metal Ions Detection 362 Small Molecules Detection 362 ECL Immunoassay 363 ECL Genosensors 365 ECL Cytosensors 366 Conclusions and Outlooks 368 Author Information 369 Corresponding Author 369 ORCID 369 Author Contributions 369 Notes 369 Biographies 369 Acknowledgments 369 References 369

The strategies of DNA immobilization and hybridization detection mechanism in the construction of electrochemical DNA sensor: A review

Abstract: In recent years, electrochemical deoxyribonucleic acid (DNA) sensor has recently emerged as promising alternative clinical diagnostic devices especially for infectious disease by exploiting DNA recognition events and converting them into an electrochemical signal This is because the existing DNA diagnostic method possesses certain drawbacks such as time-consuming, expensive, laborious, low selectivity and sensitivity DNA immobilization strategies and mechanism of electrochemical detection are two the most important aspects that should be considered before developing highly selective and sensitive electrochemical DNA sensor Here, we focus on some recent strategies for DNA probes immobilization on the surface of electrochemical transducer such as adsorption, covalent bonding and Avidin/Streptavidin-Biotin interaction on the electrode surface for specific interaction with its complementary DNA target A numerous approach for DNA hybridization detection based electrochemical technique that frequently used including direct DNA electrochemical detection and label based electrochemical (redox-active indicator, enzyme label and nanoparticles were also discussed in aiming to provide general guide for the design of electrochemical DNA sensor We also discussed the challenges and suggestions to improve the application of electrochemical DNA sensor at point-care setting

Single Cell Electrochemiluminescence Imaging: From the Proof-of-Concept to Disposable Device-Based Analysis

Abstract: We report here the development of coreactant-based electrogenerated chemiluminescence (ECL) as a surface-confined microscopy to image single cells and their membrane proteins. Labeling the entire cell membrane allows one to demonstrate that, by contrast with fluorescence, ECL emission is only detected from fluorophores located in the immediate vicinity of the electrode surface (i.e., 1–2 μm). Then, to present the potential diagnostic applications of our approach, we selected carbon nanotubes (CNT)-based inkjet-printed disposable electrodes for the direct ECL imaging of a labeled plasma receptor overexpressed on tumor cells. The ECL fluorophore was linked to an antibody and enabled to localize the ECL generation on the cancer cell membrane in close proximity to the electrode surface. Such a result is intrinsically associated with the unique ECL mechanism and is rationalized by considering the limited lifetimes of the electrogenerated coreactant radicals. The electrochemical stimulus used for luminescence g...