Search results for "chemical sensor"

Prospects for combining chemical and biological methods for integrated environmental assessment

2009

Abstract Inherently interdisciplinary, environmental assessment applied to contamination is evolving rapidly, despite associated uncertainties in methodologies and data limitations. Mixtures of known and unknown pollutants can cause toxic effects in the environment. Besides deploying a chemicals-driven strategy for the ecological risk assessment of the pollutants, it is necessary to apply and to explore biological strategies. Consequently, bioassays, biosensors and effect-directed analysis (EDA) to identify pollutants responsible of particular effects have become increasingly important. We give a broad overview of how to assess biological monitoring of ecosystems and chemical monitoring of …

A Comparative Study of Poly(Azure A) Film-Modified Disposable Electrodes for Electrocatalytic Oxidation of H₂O₂: Effect of Doping Anion.

2018

In the present paper, poly(azure A) (PAA) films were electrosynthetized in the presence of different doping anions on disposable screen-printed carbon electrodes (SPCEs). The anions used included inorganic monoatomic (chloride and fluoride), inorganic polyatomic (nitrate and sulfate) and organic polyatomic (dodecyl sulfate, DS) species. The coated electrodes thus obtained were characterized by electrochemical techniques and SEM. They showed improved electrocatalytic activities towards hydrogen peroxide oxidation compared to that of a bare SPCE. In particular, the insertion of DS anions inside PAA films provided a special sensitivity to the electrocatalysis of H2O2, which endowed these elect…

RFID Chemical Sensor: Toward the RFID Lab-on-tag

2014

Modifications électrochimiques de surfaces et dispositifs électroniques organiques

2018

Organic electronics remains a fruitful research field thanks to the diversity of molecular structures reachable by organic synthesis. Molecular materials offer convenient shaping processes, such as solution processing techniques, which can be used for the fabrication of organic devices on plastic substrates.Our works can be summarized as the elaboration of conductometric devices thanks to electrochemistry and the study of their electrical and sensing properties. They deal with two topics: the development of new transducers based on substituted polyanilines and phthalocyanines and the study of the influence of electrochemical modifications on the behavior of known devices.We first developped…

FABBRICAZIONE DI SENSORI ELETTROCHIMICI NANOSTRUTTURATI PER APPLICAZIONI NELL’INDUSTRIA ALIMENTARE E BIOMEDICHE

2023

DOPAMINE ELECTROCHEMICAL SENSOR BASED ON REDUCED GRAPHENE OXIDE AND METAL NANOPARTICLES

2019

Dopamine (DA) is one of the most important neurotransmitters released from the brain, and is involved in many different biological processes. This neurotransmitter influences the processes that involve memory, sleep, mood, learning, and so on. Besides, in the last years, dopamine concentration in human body fluids has been related to some neurodegenerative pathologies, such as Parkinson and Alzheimer’s diseases [1]. It is well known that these pathologies are due to the formation of amyloids plaques that block part of the brain. Many literature data reports that DAergic neurons (areas of midbrain where DA is synthesized) shows a different activity when amyloid plaques are present with a con…

Phosphate ions detection by using an electrochemical sensor based on laser-scribed graphene oxide on paper

2023

In this work, electrodes based on laser-scribed reduced graphene oxide were fabricated using filter paper as the substrate. To fabricate the electrodes, a water suspension of graphene oxide was filtered to produce a continuous and uniform film of graphene oxide on the filter paper surface. Subsequently, a CO2 laser was used to "write" the working, counter and reference eelctroes by reducing graphene oxide in specific areas to define complete sensors. Referecnce electrodes were then coated with a commercial Ag/AgCl conductive paste to produce a quasi Ag/AgCl reference. As fabricated devices were employed as electrochemical sensors for detection of phosphate ions in water by employing the mol…

Wearable sensor for real-time monitoring of oxidative stress

Flexible electrode based on gold nanoparticles and reduced graphene oxide for uric acid detection using linear sweep voltammetry

2021

In this work, an electrochemical sensor for uric acid determination is shown with a preliminary study for its validation in real samples (milk and urine). Uric acid can be electrochemically oxidized in aqueous solutions and thus it is possible to obtain electrochemical sensors for this chemical by means of this electrooxidation reaction. Indium tin oxide coated on flexible polyethylene terephthalate substrate, modified with reduced graphene oxide and gold nanoparticles by co-electrodeposition, was used. Electrodeposition was performed at -0.8V vs SCE for 200 s. All samples were characterized by electron scan microscopy and electron diffraction spectroscopy. A careful investigation on the ef…

Copper nanowires as higly sensitivite electrode for nitrate ions in water

Agricultural and livestock sectors are the main sources of nitrate ions contamination in water and foodstuff. [1]. High nitrate concentration is dangerous for both environment (algae overgrowth) and human health. Nitrate ions can be converted in different harmful nitrogen based compound such as NO2-, NO, N-nitroso compounds [2] that are responsible of several diseases such as cancer, Parkinson [3-4]. For these reasons, the Environmental Protection Agency, has established the maximum amount of nitrate ions in drinkable water at 44 mg/l, limit that is valid in many European countries [5]. Generally, spectroscopy techniques are the most used because allow to carry out analyses with high precis…