Valentina Pifferi

• PhD in Chemical Sciences and Technologies
• PostDoc Position at University of Milan

Fouling and passivation are the major drawbacks for a wide applicability of electroanalytical sensors based on nanomaterials, especially in biomedical and environmental fields. The production of highly engineered devices, designed ad hoc for specific applications, is the key factor in the direction of overcoming the problem and accessing to effecti...

The potential for on site applications of a SiO2-Ag NPs-TiO2 self-cleaning electrode was demonstrated. Dopamine was used both as the analyte and the fouling agent. Three different UV lamps (a powerful lamp (45 mW cm-2) for photocatalysis, a TLC lamp and a commercial LED torch) were studied. After fouling, total recovery of the electroanalytical per...

Silicon wafer is the material of choice for microfabrication. However, the development of innovative on-chip electrochemical sensors using silicon is hampered by its poor electrochemical properties. In this article we demonstrate how grafted-from micropatterned polymer brushes dramatically enhance the electrochemical response of silicon electrodes....

Photocatalytic mineralization of o-toluidine in aqueous media under UV/solar irradiation was achieved by bare and bismuth doped zinc oxide nanoparticles. By adopting different analytical approaches a reaction mechanism is proposed, explaining the differences in photodetoxification performances.

A bimodal sensor able to effectively detect cetirizine, an antihistaminic drug, was proposed. The device is based on the catalytic properties of silver and the photoactivity of TiO 2 and can be used as dual electrochemical‐photoelectrochemical sensor, with good performances in cetirizine quantification both through the molecule's reduction and its...

Nitrates (NO3‐) are crucial in agricultural practices and the food industry, but their excessive presence in water can lead to adverse health effects. Their leaching into water sources necessitates regular monitoring. This study introduces a novel bimodal electrochemical (EC)/photoelectrochemical (PEC) sensor, utilizing copper‐modified graphitic ca...

A novel dual-mode sensor based on the in-situ coupling of electrochemical (EC) and fluorescence (FL) assay for o-toluidine and cholesterol detection is reported. The detection platform was constructed by assembling nitrogen doped graphene quantum dots (N-GQDs), benzoquinone (BQ) and β-cyclodextrin (β-CD). Once the analyte is captured by β-CD, a con...

Abstract Invited for this issue's Front Cover is the group of Electroanalytical Chemistry of Prof. Luigi Falciola. The Cover Feature shows the photoelectrochemical sensor prepared by covering AuNPs with a thin layer of TiO2. The obtained hybrid material, which exploits synergistically the properties of its components, was used to monitor ciprofloxa...

A photoelectrochemical sensor composed of a heterojunction between titanium dioxide and gold nanoparticles was fabricated and used for the determination of ciprofloxacin, a widely used, but environmentally toxic third‐generation antibiotic. This material has been extensively characterized from the morphological, electrochemical and photoelectrochem...

The establishment of novel disruptive technologies represents a common requirement for the sustainable development as reported in the 2030 agenda established by United Nations. As demonstrated by the Covid-19 pandemic, and furtherly highlighted by the current global challenges, i.e. precision agriculture, decentralized testing, personalized medicin...

Hydrophilic cyclodextrin nanosponges were prepared by the oxo-Michael polyaddition in an aqueous solution at pH > 10 of α-, β-, and γ-cyclodextrin with 1,4-bisacryloylpiperazine or 2,2-bisacrylamidoacetic acid. These nanosponges and, for comparison purposes, their precursor cyclodextrins were tested as sorbents of o-toluidine, a carcinogenic wastew...

Electrochemical sensors integrating hybrid nanostructured platforms are a promising alternative to conventional detection techniques for addressing highly relevant challenges of heavy metal determination in the environment. Hybrid nanocomposites based on graphene derivatives and inorganic nanoparticles (NPs) are ideal candidates as active materials...

Nanocomposites are at the heart of the present nanotechnology revolution in several strategic fields, including Green Chemistry, sensors and pollutant remediation. The promising and extensively examined nanotitania photocatalysts have performances hampered by the rapid recombination of photogenerated charge carriers. To better understand these mate...

Fouling and passivation are the major drawbacks for the broad applicability of electroanalytical sensors, particularly those based on nanomaterials, especially in biomedical and environmental fields. The production of highly engineered devices, based on innovative and smart materials, ad-hoc designed for specific applications, is critical in overco...

An easy and reliable method based on a novel electroanalytical nanostructured sensor has been developed to perform quantification of vitamin C in commercial and fortified cow-milk-based formulae and foods for infants and young children. The work is motivated by the need of a reliable analytical tool to be applied in quality control laboratories for...

The interest of the scientific community for nanotechnologies and nanomaterials was born in 1959, on the occasion of the annual meeting of the American Physical Society, when a new approach began with which to consider and manipulate matter on a micro- and nano-metric scale. The subsequent increase in the use of nanomaterials in scientific research...

The development of high-performing sensing materials, able to detect ppb-trace concentrations of volatile organic compounds at low temperatures, is required for the development of next-generation miniaturized wireless sensors. Here, we present the engineering of selective room-temperature chemical sensors, comprising of highly porous tin dioxide (S...

Besides wastewater treatments for the removal of contaminants, a key point in water quality assessment is the continuous monitoring and detection of pollutants with the aim of verifying, in addition to the pureness of water, the effectiveness of such treatment methods. In this context, in this chapter, the actual more used detection methods for the...

Three types of carbon nanofibers (pyrolytically stripped carbon nanofibers (PS), low-temperature heat treated carbon nanofibers (LHT), and high-temperature heat treated carbon nanofibers (HHT)) with different graphitization degrees and surface chemistry have been used as support for Au, Pd, or bimetallic AuPd alloy nanoparticles (NPs). The carbon s...

One of the key issues of electrochemical sensing in complex matrices is the presence of interferents which can foul the electrode and block the access to the active surface. A possible strategy to promote selectivity is based on the use of interference-abating layers, which can however significantly hamper the sensor response by limiting the analyt...

Despite the poor solubility in organic solvents, poly (3,4-ethylenedioxythiophene) (PEDOT) is one of the most successful conducting polymers. To improve PEDOT conductivity, the dopants commonly used are molecules/polymers carrying sulfonic functionalities. In addition to these species, sulfonated polyarylethersulfone (SPAES), obtained via homogeneo...

To overcome the well-known technical problems of Poly(3,4-Ethylenedioxythiophene) (PEDOT), i.e. difficult processability and patterning, due to its poor solubility in common organic and inorganic solvents, PEDOTs characterized by a full miscibility in the reaction solvents used, were successfully synthesized by a direct oxidative polycondensation r...

In this chapter, a quick excursus of metal-free doped carbon materials for the modification of electrodes to be used in electroanalytical sensors has been made. After a brief introduction to the different methods available for modified electrode preparation, the most used carbonaceous materials doped with heteroatoms (B, N, O, P, S) have been consi...

Au nanorods (NRs) modified nanostructured TiO2/ITO electrodes have been fabricated and characterized in order to develop a biosensing platform for the photoelectrochemical determination of microRNAs. The proposed method is based on the use of thiolated DNA capture-probes (CPs) immobilized onto Au NR surface. The Au NRs are chemically bound at the s...

Herein, we report a one-pot wet chemical method adopted to synthesize ad hoc MnO2 nanoparticles. By varying both the manganese salt precursors (e.g. sulphate or chloride) and the oxidizing agents (e.g. ammonium persulphate, potassium permanganate or potassium bromate), we succeeded in tailoring MnO2 structural, morphological and surface features. H...

The innovative photoelectrochemical properties of multifunctional nanomaterials are here investigated for the development of biosensing platforms for rapid and sensitive detection of a class of cancer biomarker candidates, known as microRNAs. Many different transducers have been proposed, so far, for microRNA detection. Recently, with the emergence...

Concentrated Animal Feeding Operations (CAFOs) are widely present all over the world due to the high population demand for food and products of animal origin. However, they have generated several environmental concerns, including odour nuisance, which affects people health and quality of life. Odours from livestock are a very complex mixtures of mo...

The modification of a silicon surface with ultrathin poly(styrene) brushes, obtained by grafting-from, results in a dramatic increase in capacitance as shown by cyclic voltammetry. This difference in the behavior of silicon and poly(styrene) brush-modified silicon electrodes is amplified when the electrochemical measurements are performed under UV...

A concerted theoretical and experimental investigation of the silver/anatase hybrid nanocomposite, a very promising material for advanced sensing applications, is presented. We measure its exceptional electrochemical virtues in terms of current densities and reproducibility, providing their explanation at the atomic-scale level, and demonstrating h...

The effect of depositing different numbers of insulating layers from a silica sol onto an ITO support was investigated to elucidate the changes occurring to diffusion and transfer mechanisms compared with bare electrodes. The electrochemical studies highlighted unexpected trends, which were discussed with respect to literature models and interprete...

An optically transparent and UV-light active anode, characterized by high (photo)conductivity, charge mobility and exciton lifetime, based on graphene, grown by CVD, decorated with colloidal TiO2 nanocrystals (NCs), has been fabricated, by a direct and facile solution-based procedure. TiO2 NCs anchor onto graphene by means of π–π stacking interacti...

The imaging of drugs inside tissues is pivotal in oncology to assess whether a drug reaches all cells in an adequate enough concentration to eradicate the tumor. Matrix-Assisted Laser Desorption Ionization Mass Spectrometry Imaging (MALDI-MSI) is one of the most promising imaging techniques that enables the simultaneous visualization of multiple co...

The photodegradation of the highly toxic o-toluidine pollutant was deeply investigated both under UV and solar irradiations by using three different semiconductors: pure ZnO, Bi-impregnated ZnO, and Bi2O3 nanopowders (synthesized by precipitating method). All the samples were deeply characterized on structural, morphological, surface, and optical p...

Herein we report the photodegradation of highly toxic o-toluidine in aqueous media (under UV irradiation), by using home-made bare and bismuth-doped ZnO nanoparticles. The latter powder was prepared by both a traditional impregnation method and by an innovative sol-gel synthesis, obtained using bismuth nitrate as precursor. Moreover, synthetic cond...

In this work, the manufacturing and characterization of an optically transparent and UV-light photoactive anode, formed of graphene grown by chemical vapor deposition (CVD) decorated with a close packed multilayer nanostructured layout of colloidal TiO2 nanocrystals (NCs), has been reported. The hybrid material was prepared by a facile solution-bas...

Pharmaceutics and personal care products (PPCPs) are raising growing concern due to their widespread usage and resistance to conventional remediation techniques. Several of them raise significant health and environmental concerns, especially when present in complex mixtures. Due to their chemical resistance, Advanced Oxidation Processes (AOPs) are...

Mass Spectrometry Imaging (MSI) is a widespread technique used to qualitatively describe in two dimensions the distribution of endogenous or exogenous compounds within tissue sections. Absolute quantification of drugs using MSI is a recent challenge that just in the last years has started to be addressed. Starting from a two dimensional MSI protoco...

Hetero-nanoparticles represent an important family of composite nanomaterials that, in the last years, is attracting ever growing interest. Here, we report a new strategy for the synthesis of water dispersible cobalt ferrite nanoparticles (CoxFe3-xO4 NPs) decorated with ultrasmall (2-3 nm) gold nanoparticles (Au NPs). The synthetic procedure is bas...

The photocatalytic degradation of dIfferent pharmaceuticals belonging to the class of emerging contaminants was studied both in the case of single pollutants and their mixture. An immobilized TiO2 system was developed and tested as well as the TiO2 nanopowder.

A composite electrode with a sandwich structure combining the properties of silver nanoparticles and a titania photoactive layer was used for the electroanalytical detection, by differential pulse voltammetry, of three neurotransmitters: dopamine, norepinephrine, and serotonin. The three analytes were determined at low detection limits (around 0.03...

A combination of the electroactive polymer poly(brilliant green) (PBG) or conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) with carbon nanotubes to obtain CNT/PBG and CNT/PEDOT modified carbon film electrodes (CFE) has been investigated as a new biosensor platform, incorporating the enzymes glucose oxidase (GOx) as test enzyme, alcohol o...

The influence of primary/tertiary amines in Oil-in-Water emulsions (as Metal Working Fluids (MWFs) towards brass) is evaluated in both pure water and 5% O/W emulsion. Physical properties, wetting, lubricating and corrosion behaviors are finely investigated. Experimental results show that the number of carbon atoms in amines plays a pivotal role in...

Au-based catalysts are widely used in important processes because of their peculiar characteristics. The catalyst performance depends strongly on the nature and structure of the metal nanoparticles, especially in the case of bimetallic catalysts where synergistic effects between the two metals can be occasionally seen. In this paper, it is shown th...

Linear sulphonated poly(arylethersulphone) (SPAES) membranes were tested and compared with Nafion, as electrode modifiers for electroanalytical purposes. Different preparation parameters were evaluated: casting solvent, method of drying and storage, polymer ionic moieties counter-ion. In particular, the casting solvent seems to play a key role in t...

pH-Switchable electrochemical properties are demonstrated for the first time for native oxide-coated silicon wafer electrodes. Ultrathin and ultrathick pH-responsive poly(methacrylic acid) (PMAA) brushes, obtained by surface-initiated atom transfer radical polymerization, were used to achieve redox gating. PMAA brushes are reversibly switched betwe...

The vapor-phase deposition of triethoxy(octyl)silane and 1H,1H,2H,2H-perfluoroctyltriethoxysilane on silica substrates was studied at different temperatures (70 - 150 °C). An original combination of spectroscopic (13C and 29Si solid state NMR, FTIR), electrochemical (CV, EIS) and surface (surface free energy determinations, AFM) characterization te...

This paper aims to provide a summary of our contribution in the field of the determination, by electroanalytical techniques, of some contaminants of emerging concern at trace level, particularly focusing the attention on the use of nanomaterials and innovative polymers for electrode modification.

Commercially available multiwalled carbon nanotubes (CNTs) were decorated by size-controlled and stable silver nanoparticles (NPs) using a sol immobilisation technique. Silver nanoparticles were in some cases protected by polyvinyl-alcohol (PVA). These materials were used to prepare different glassy carbon modified electrodes, which were tested in...

The aim of this study was to determine the concentration and the variations of salivary glucose in healthy patients who were sampled at five different intervals during the day. Samples of un-stimulated saliva have been collected from 21 healthy patients using the drooling technique and they were divided into two categories. In the first category, p...

A linear amphoteric poly(amidoamino acid), L-ARGO7, is prepared by Michael-type polyaddition of L-arginine with N,N'-methylenebisacrylamide. Chain-extension of acrylamide end-capped L-ARGO7 oligomers with piperazine leads to high-molecular-weight copolymers in which L-arginine maintains its absolute configuration. Acid/base properties of L-ARGO7 po...

The use of commercially available Screen Printed Electrodes (SPEs) in Pulsed Voltammetric techniques for the determination of carcinogenic compounds, (namely furan, benzidines and chromium (VI)), is presented. The advantages related to the SPEs disposability and to the electrodes protection with Nafion® membrane for fouling prevention is shown.

The aim of this manuscript is to develop a combined method for the detection and remediation of As(III) species in aqueous environment. Linear sweep adsorptive stripping voltammetric technique, based on the use of commercially available gold nanoparticle-modified screen-printed electrodes is proposed to detect ultra traces of As(III) in solution. T...

Nafion® stabilized silver nanoparticles modified Glassy Carbon electrodes were prepared with a very simple procedure depositing onto the Glassy Carbon support a suspension of nanomaterials in Nafion®. Electrodes were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and energy...

In recent years, titanium dioxide has received ever growing interest, thanks to its promising applications in numerous fields such as environmental remediation, H2 generation and photovoltaics. Here, transparent and mechanically robust TiO2 films are deposited by a simple and inexpensive electrochemically assisted procedure on various kinds of subs...

Nano-TiO2 is certainly the most studied semiconductor for environmental purposes. Here, a template synthesis using block copolymers is combined to Bi promotion to the purpose of enhancing the TiO2 photocatalytic activity by modulating the oxide surface area and porosity as well as by slowing down the electron–hole recombination. Three block copolym...

Carbon- and platinum-based screen-printed electrodes have been tested, in comparison with standard GC and Pt electrodes, for detecting benzidine, an organic carcinogenic synthetic compound mainly used as intermediate in production of azo-dyes. The methodology consists in a DPV in acidic media and offers excellent results in terms of large dynamic c...

A rapid, precise and accurate electroanalytical methodology for the determination of furan, a possible human carcinogen, is proposed. The method is based on the use of Square Wave Voltammetry (SWV) on a platinum disk or on platinum based Screen Printed Electrodes, performed in acetonitrile with tetrabutylammoniumperchlorate as supporting electrolyt...