Search results for "electrochemical sensor"

Copper nanowire array as highly selective electrochemical sensor of nitrate ions in water

2020

Contamination of water with nitrate ions is a significant problem that affects many areas of the world. The danger from nitrates is not so much their toxicity, rather low, as their transformation into nitrites and in particular into nitrosamines, substances considered to be a possible carcinogenic risk. For this reason, European legislation has set the maximum permissible concentration of nitrates in drinking water at 44 mg/l. Thus, it is clear that a continuous monitoring of nitrate ions is of high technological interest but it must be rapid, easy to perform and directly performed in situ. Electrochemical detection is certainly among the best techniques to obtain the above requirements. In…

Photoelectrochemical Bisphenol S Sensor Based on ZnO‐Nanoroads Modified by Molecularly Imprinted Polypyrrole

2019

Molecularly imprinted polymers are important tools for the design of sensors and other molecular recognition based analytical systems. In this paper the development of a photoelectrochemical sensor for selective bisphenol determination is reported. The sensor is based on a glass/ZnO/MIP‐Ppy structure consisting of glass modified by a ZnO layer (glass/ZnO), which is functionalized by molecularly imprinted conducting polymer polypyrrole (MIP‐Ppy). The sensitivity of the sensor to bisphenol is in the range of 0.7–12.5 µm. Selectivity tests to other bisphenolic compounds are performed. Some aspects of a photoinduced response mechanism in glass/ZnO/MIP‐Ppy nanostructures are predicte…

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…

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…

Ni/NiO thin film Sensors for Mercury ions detection by Square wave anodic stripping voltammetry

2018

Square wave anodic stripping voltammetry (SWASV) is considered a very interesting electrochemical method for heavy metals detection in comparison to conventional techniques [1]. The main features of this technique are the high sensitivity and reproducibility (standard deviation lower than 5%), besides, the limit of detection is in the ppb level so is comparable with standard techniques such as AAS or ICP, the instrumentation is very inexpensive and easy to use and the detection time is very low. Among heavy metals, mercury is one of the most toxic for both environment and humans. In fact, it may cause serious health problems to brain, kidney and DNA. The concentration limit imposed by US En…