1,721,106 research outputs found
Electroanalysis with modified electrodes: from the use of simple nanomaterials to engineered nanohybrids
No full textIn recent years, electroanalysis has witnessed a great growth in the employment of nanomaterials and/or in the use of polymer films to develop smart “modified electrodes”, particularly suitable for trace analysis of contaminants of emerging concern [1-2]. High surface to volume ratio, analyte adsorptive preconcentration capability and appropriate nano-dimensions enormously increase the availability of interaction sites for the analyte, enhancing the sensitivity and lowering the detection limits. Moreover, the small dimensions may allow controlling the sensing process locally, in terms of change in the mass transport regime (e.g. from planar to convergent or to thin-layer), improving sensors performances. These effects are particularly maximized in the case of well-ordered structures. Furthermore, the use of appropriately tailored nanohybrids, characterized by synergistic functionalities based on the generation of heterojunctions has paved the way towards promising applications, obtaining “brave new materials”, with physico-chemical properties which are not only the sum of the precursors’ ones.
In this presentation, experimental results obtained by our group, working with different nanomaterials and nanohybrids for the modification of the electrodes for electroanalytical applications are presented and discussed:
- electrodes modified with appropriately functionalized Carbon NanoTubes (CNT) [3];
- electrodes modified with Sulphonated Poly (Aryl Ether Sulphones), a new class of polymers, ad hoc tailored for electroanalytical applications [4];
- electrodes modified with bimetallic Au/Pd and Au/Pt systems [5];
- photorenewable electrodes based on silver nanoparticles and titania [6];
- (photo)electrochemically active functional hybrids of multilayer CVD graphene decorated with colloidal TiO2 nanocrystals [7];
- (photo)electrochemically active functional hybrids of graphene decorated with colloidal gold nanoparticles.
References
[1] D.T. Pierce, J.X. Zhao, Trace Analysis with Nanomaterials. Wiley-VCH, 2010.
[2] “Electroanalysis at the Nanoscale”, Faraday Discuss., vol. 164, 2013.
[3] V. Pifferi, G. Cappelletti, C. Di Bari, D. Meroni, F. Spadavecchia, L. Falciola, “Multi-Walled Carbon Nanotubes (MWCNTs) modified electrodes: Effect of purification and functionalization on the electroanalytical performances”, Electrochimica Acta, vol. 146, pp. 403-410, 2014.
[4] L. Falciola, S. Checchia, V. Pifferi, H. Farina, M. A. Ortenzi, V. Sabatini, “Electrodes modified with sulphonated poly(aryl ether sulphone): effect of casting conditions on their enhanced electroanalytical performance”, Electrochimica Acta, vol. 194, pp. 405-412, 2016.
[5] V. Pifferi, C. E. Chan-Thaw, S. Campisi, A. Testolin, A. Villa, L. Falciola, L. Prati, “Au based catalysts: electrochemical characterization for structural insights”, Molecules, vol. 21(3), pp. 261, 2016.
[6] G. Soliveri, V. Pifferi, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, K. Sparnacci, L. Falciola, “Self-cleaning properties in engineered sensors for dopamine electroanalytical detection,“ Analyst, vol. 140, pp. 1486-1494, 2015.
[7] C. Ingrosso, G.V. Bianco, V. Pifferi, P. Guffanti et al., “Enhanced Photoactivity and Conductivity in Transparent TiO2 Nanocrystals/Graphene Hybrid Anode”, J. Mat. Chem. A, in press, 2017
Ion-exchange polymers modified electrodes for electroanalytical applications
No full textIn the last couple of decades, electrode coatings based on proton conducting polymers were extensively adopted in the electroanalytical field for the preparation of modified electrodes to be used as more performing sensors. These devices offer several advantages: they reduce adsorption phenomena, suppress the inclusion of interfering species, protect the electroactive surface from passivation and fouling, act as pre-concentrating agents towards selected analytes, modify the process kinetics and diffusion yielding high sensitivity and selectivity [1-3]. Commercially available polymers most currently found in the literature as electrode modifiers are Nafion®, Eastman AQ55® (both cation-exchange polymers), and Tosflex® (anion-exchange polymer). Among them, Nafion® is the most widely adopted ion-exchange polymer, founding many diverse electroanalytical applications although initially developed for fuel cell membranes. Scarce use of other polymers was present in the Literature.
In this context, in this presentation we would like to show some results on the use of sulphonated poly(aryl ether sulphone) (SPAES), an innovative polymer in this field, whose properties can be appropriately designed, tailored and used as electrode modifier for electroanalytical applications. Since connectivity and morphology of the modifier polymer are critical factors in controlling conductivity, stability, active surface and diffusion mechanism of the modified electrode, much attention was devoted to the polymer casting conditions and procedure on the glassy carbon support electrode. Four solvents, characterized by different boiling points and polarity were tested: dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), N-methylpyrrolidone (NMP). In the case of NMP a better membrane organization, probably allowing a thin layer diffusion mechanism or a preconcentration step, appears to be responsible for the increased peak currents.
Moreover, since the effect of polymer porosity seems to play a crucial role in electroanalytical performances, particularly modifying the absorption and pre-concentration of the analyte or its diffusion mechanism (from planar to convergent or to thin-layer [4-5]), an ad hoc study was performed considering different modified electrodes obtained by electrospinning a PLLA polymer in different structures. Three types of porous layers were obtained (nanometric (300-600 nm), micrometric (2-4 μm) and meso/microporous micrometric (2-5 μm)) in three different thickness. The results show a strong effect of mesoporosity in the enhancement of the CV peak height, which is fully consistent with a thin-layer model diffusion mechanism inside the porous structure [5-6].
References
[1] G. Inzelt, M. Pineri, J. Schultze, M. Vorotyntsev, Electrochim. Acta 45, 2000, pp 2403–2421.
[2] P. Ugo, L.M. Moretto, F. Vezzà, Chem. Phys. Chem. 3, 2002, pp 917–925.
[3] C. Gouveia-Caridade, C. Brett, Strategies, Curr. Anal. Chem. 4, 2008, pp 206–214.
[4] I. Streeter, R. Baron, R.G. Compton, J. Phys. Chem. C 111, 2007, pp 17008–17014.
[5] M.C. Henstridge, E.J.F. Dickinson, M. Aslanoglu, C. Batchelor-McAuley, R.G. Compton, Sensors Actuators B Chem. 145, 2010, pp 417–427.
[6] V. Pifferi, G. Cappelletti, C. Di Bari, D. Meroni, F. Spadavecchia, L. Falciola, Electrochim. Acta 146, 2014, pp 403-410.
Acknowledgements
This work has been supported by MIUR (Ministero dell’Istruzione, dell’Università e della Ricerca) in the framework of the PRIN 2012 Project (20128ZZS2H)
A Concerted Electrochemical and Theoretical Investigation of the Ag/TiO2 nano-heterojunction
Full text linkSuitably designed nano-heterojunctions are able to enhance synergistic functionalities of different materials yielding to “brave new systems” with innovative and sometimes unexpected physicochemical properties [1]. However, the complete understanding of these devices has to be deeply studied. In this work, a concerted theoretical and electrochemical investigation is proposed to gain insights into a metal-semiconductor interface, namely that created by the silver/anatase hybrid nanocomposite, a promising material for advanced sensing applications [2]. In particular, it provided the first photorenewable and anti-fouling sensor device, enhancing the analytical limits in terms of accuracy, sensitivity, detection limits, and photoactivity [3]. Furthermore, the hybrid material is proven to be extremely robust against aging, showing complete regeneration, also after one-year storage.
The electrochemical/electroanalytical virtues of the Ag/TiO2 junction were evaluated in terms of current densities and reproducibility, providing their explanation at the atomic-scale level and demonstrating how and why the final device can act as silver-cation positive electrode [4]. Moreover, Cyclic Voltammetry and Electrochemical Impedance Spectroscopy were used in combination with periodic plane-wave DFT calculations, giving comparable qualitative but also quantitative results. In particular, we theoretically estimated the overall amount of electron transfer toward the semiconductor side of the interface at equilibrium and suitably designed electrochemical experiments, which strictly agree with the theoretical charge transfer estimates. Moreover, photoelectrochemical measurements and theoretical predictions show the unique permanent charge separation occurring in the device [4].
[1] A.V. Emeline, V.N. Kuznetsov, V.K. Ryabchuk, N. Serpone, Environ. Sci. Pollut. Res., 2012, 19, 3666–3675.
[2] G. Soliveri, V. Pifferi, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, K. Sparnacci, L. Falciola, Analyst, 2015, 140, 1486–1494.
[3] V. Pifferi, G. Soliveri, G. Panzarasa, G. Cappelletti, D. Meroni, L. Falciola, Anal. Bioanal. Chem., 2016, 408, 7339–7349.
[4] G. Di Liberto, V. Pifferi, L. Lo Presti, M. Ceotto, L. Falciola, J. Phys. Chem. Lett., 2017, 8, 5372–5377
Silver nanoparticles/nanostructured TiO2 interface: a photo-renewable “silver-ions electrode” for neurotransmitters detection
No full textIn recent years the use of hybrid nanomaterials, characterized by unprecedented behaviours and features, has paved the way towards promising applications in many fields. The synergistic functionalities provided by these nanocomposites, based on the generation of heterojunctions, allow to obtain “brave new materials”, with physico-chemical properties which are not only the sum of the precursors’ ones. Although the Literature has used plenty of these new devices for different applications, the complete understanding of the phenomena deeply located inside these interfaces is still to be clarified.
In this context, we propose this theoretical and electrochemical concerted study to help in the understanding of the Ag-TiO2 interface properties. In particular, silver nanoparticles were embedded in a TiO2 (anatase polymorph) photoactive layer in a sandwich-like nanostructured electrode, which was (photo)electrochemically characterized by cyclic voltammetry and electrochemical impedance spectroscopy. According to the theoretical and experimental findings it could be concluded that the device may be considered as a “positively charged silver nanoparticles-based electrode”, with positively ionized surface silver atoms protected by the titania layer, which holds a partial negative charge. The final sensor performed efficiently in the electroanalytical determination of some neurotransmitters in simulated biological matrices presenting interesting results in terms of sensitivities, detection limits and photoactivity, providing also the first photo-renewable sensor device, capable of overcoming the fouling and passivation of the electrode surface, an unavoidable drawback during the detection of this kind of analytes [1-3].
Acknowledgments
This work has been supported by Fondazione Cariplo (Italy), grant no. 2014-1285 and by the MIUR National Project PRIN 2012 (prot. 20128ZZS2H).
References
1. G. Soliveri, V. Pifferi, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, K. Sparnacci, L. Falciola, Analyst, 2015, 140, 1486-1494.
2. V. Pifferi, G. Soliveri, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, L. Falciola, RSC Advances, 2015, 5, 71210-71214.
3. V. Pifferi, G. Soliveri, G. Panzarasa, G. Cappelletti, D. Meroni, L. Falciola, Anal. Bioanal. Chem., 2016, 7339-7349
Carbon-based modified electrodes for o-toluidine voltammetric detection
No full textDifferent modified electrodes, based on the screen-printing technology (SPE) or prepared by the casting procedure using different carbon materials (carbon nanotubes, graphene, graphite,...) have been prepared and fully characterized by Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). Also the effect of the use of different supporting materials was studied.
The final devices have been compared with GC electrode, for the development of a new electroanalytical methodology for the detection of o-toluidine, an organic carcinogenic synthetic pollutant mainly used as an intermediate in production of azo-dyes, already studied by the research group in a previous work [1].
The developed method is based on voltammetric techniques, which allow to achieve excellent results in terms of large dynamic concentration ranges, high accuracy and precision and low limits of detection and quantification [2]. The use of nanomaterials (in particular carbon nanotubes) enhances the potentialities of the method, improving sensitivity and lowering detection limits [3].
In particular, o-toluidine was detected using Linear Sweep Voltammetry in the range 1.5-7 ppm, obtaining a limit of detection of 0.16 ppm and excellent apparent recovery factors (102%) and repeatability, in comparison with carbon based-screen printed electrodes, which presented problems of fouling, probably due to polymerization products.
This new method was used for the determination of o-toluidine during its photodegradation mediated by ZnO photocatalyst, showing better performances than C-SPE and comparable with HPLC.
Moreover, the methodology was also employed to monitor o-toluidine absorption by cyclodextrine nanosponges based on hydrogel polyamidoamines (PAA), allowing to discriminate among various types of resins and to obtain absorption kinetic parameters.[1] L. Falciola, V. Pifferi, E. Mascheroni, Electroanalysis , 24, (2012), 767.
[2] C.M.A. Brett, A.M. Oliveira-Brett, J. Solid State Electrochemistry, 15, (2011), 1487.
[3] J.J. Gooding, Electrochimica Acta, 50, (2005), 3049
Gold or silver-decorated multiwalled carbon nanotubes modified electrodes for trace electroanalysis
No full textTrace analysis [1] (i.e. the analysis of analytes in concentration low enough to cause difficulty, generally under 1 ppm) albeit very challenging, in the last years has shown a tremendous growth, prompted by the urgent need of many International Organizations (US Environmental Protection Agency EPA, U.S. Food and Drug Administration FDA, European Food Safety Authority EFSA, World Health Organization WHO) looking for new analytical techniques for the detection of different molecules in different and increasingly more complex matrixes.
The determination of trace analytes requires reliable and robust analytical methods characterized by high level of sensitivity, precision, accuracy, selectivity and specificity. Among different analytical techniques electroanalytical ones and particularly those based on pulsed voltammetry, seem to be a promising independent alternative in terms of very high precision, accuracy and sensitivity. Advantages in using these latter systems lie on simplicity of use, portability, easy automation and possibility of on-line and on-site monitoring without sample pre-treatments and low costs.
In this context, the use of nanosized and/or nanostructured materials for the modification of electrodes is growing in importance, with the aim of increasing the affinity for the analyte, increasing sensitivity, lowering the limits of detection and minimizing or completely avoiding interferences, i.e. increasing their selectivity. Carbon nanomaterials coupled with metal nanoparticles [2, 3] present unique peculiar properties, dependent on metal nanoparticle size and shape and therefore are extensively employed in electroanalysis as tunable materials.
In this communication, we will present the electrochemical characterization (by Cyclic Voltammetry and Electrochemical Impedance Spectroscopy) and the electroanalytical application of modified electrodes based on carbon nanotubes decorated with gold or silver nanoparticles. In particular, the synergic effect of both metal and carbon nanomaterials was investigated. Moreover, the use of PVA protective polymer for metal NPs allows better electroanalytical performances due to the protection from oxidation, fouling products and interferences. The optimized electrodes were then tested for the determination of relevant or toxic analytical substances for environmental monitoring such as glycerol and chlorinated compounds, with interesting results [4].
[1] D.T. Pierce, J.X. Zhao, Trace Analysis with Nanomaterials, Wiley-VCH, Weinheim (Germany), (2010).
[2] L. Rassaei, M. Amiri, C.M. Cirtiu, M. Sillanpaa, F. Marken, M. Sillanpaa, Trends in Analytical Chemistry 30(11) (2011) 1705-1715.
[3] V. Pifferi, V. Marona, M. Longhi, L. Falciola, Electrochimica Acta 109 (2013) 447-453.
[4] V. Pifferi, G. Facchinetti, A. Villa, L. Prati, L. Falciola, Catalysis Today, (2014), in press, doi:10.1016/j.cattod.2014.10.00
Electrodes modified by sulphonated Poly (Aryl Ether Sulphone) (S-PES) for electroanalytical applications
No full textThe use of polymeric materials for electrodes modification, with the aim of increasing the affinity for the analyte, increasing sensitivity, lowering the limits of detection and minimizing or completely avoiding interferences is becoming an interesting challenge in recent electroanalytical methods. Although scarcely characterized or appropriately designed for the modification of electrodes, thanks to its large use in fuel cell devices, Nafion® is one of the most popular polymer also in electroanalytical applications [1].
Poly (Aryl Ether Sulphones), commonly called PES, are well-known engineered thermoplastic materials [2], with excellent properties thanks to their aromatic skeleton and charged groups, such as thermal and mechanical strength, resistance to oxidation and acid catalyzed hydrolysis. Moreover, they present high glass transition temperature, good solubility in polar aprotic and halogenated solvents, radiation stability, low flammability and toughness, together with low costs.
In this context, sulphonated Poly (Aryl Ether Sulphone) (S-PES) was studied as a new material for the production of modified electrodes in comparison with Nafion®.
The modified electrodes are fully characterized by cyclic voltammetry and Electrochemical Impedance Spectroscopy (EIS).
Different parameters have been studied: the quantity and the form (acidic, salt, linear, branched,...) of the polymer, different IECs, its method of drying, the casting solvent, its stability in air or solution.
In particular, as the Figure shows, 1 % linear PES in the acidic form, dried at 25 °C in a oven, after deposition from a N-Methylpyrrolidone solution, appears to present the best performances in terms of higher voltammetric peak currents, more stability and less resistive behaviour, superior to Nafion®, maintaining the partial electrochemical and chemical reversibility and the diffusive control.
[1] V. Pifferi, V. Marona, M. Longhi, L. Falciola, Electrochimica Acta, 109, (2013), 447-453. [2] R.T.S. Muthu Lakshmi, J. Meier-Haack, K. Schlenstedt, H. Komber, V. Choudhary and I.K. Varma, Reactive and Functional Polymers, 66 (6), (2006), 634–644
Electrochemical and theoretical investigation of the silver nanoparticles/TiO2 interface: the “silver-ion electrode”
No full textA sandwich-like structure electrode of silver nanoparticles embedded in a titania (anatase polymorph) photoactive layer was prepared [1-2] and electrochemically characterized by cyclic voltammetry and electrochemical impedance spectroscopy.
In comparison with literature data on bare silver nanoparticles-modified electrodes [3-5], the new device features a pronounced electrocatalytic effect on the silver oxidation peak (Fig. a) together with a great increase in the current intensity. Plane-wave DFT calculations, performed using the VASP code, described the composite junction as a distorted bulk Ag structure, commensurate with the periodicity of the (101) face of the I41/amd TiO2 polymorph. The silver atoms close to the semiconductor were found to gain a partially positive charge, quickly decreasing with the distance from the TiO2 surface.
These joint theoretical and experimental evidences demonstrate that the device could be considered as a “positively charged silver nanoparticles-based electrode”, with positively ionized surface silver atoms protected by the titania layer, which holds a partial negative charge. This peculiar electrode structure shows interesting properties, among which self-cleaning ability, to be conveniently used for sensor applications.
References
[1] G. Soliveri, V. Pifferi, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, K. Sparnacci, L. Falciola, Analyst, 140, (2015), 1486 – 1494.
[2] V. Pifferi, G. Soliveri, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, L. Falciola, RSC Advances, 5, (2015), 71210 – 71214.
[3] O. S. Ivanova, F. P. Zamborini, J. Am. Chem. Soc., 132, (2010), 70–72.
[4] G. Chang, J. Zhang, M. Oyama, K. Hirao, J. Phys. Chem. B, 109, (2005), 1204-1209.
[5] S.E. Ward Jones, F.W. Campbell, R. Baron, L. Xiao, R.G. Compton, J. Phys. Chem. C, 112, (2008), 17820–17827.
Acknowledgements
This work has been supported by Fondazione Cariplo (Milano, Italy), grant no. 2014-1285. We acknowledge the CINECA and the Regione Lombardia award under the LISA initiative (grant SURGREEN) for the availability of high performance computing resources. We also thank the Chemistry Department for funding through the Development Plan of Athenaeum grant – line B1 (UNIAGI 17777)
A Concerted Investigation For Metal/Semiconductor Nanointerface : Interlayer Charge Transfer At Ag/TiO2
Full text linkIn the field of hybrid materials, suitably designed nanoheterojunctions enhance synergistic functionalities and allow to obtain “brave new materials” with physicochemical properties that are not simply the addition of the precursors’ ones, but are completely new, different, and sometimes unexpected. For these reasons, the use of them has paved the way toward promising applications in many fields, such as electrocatalysis, photocatalysis, electroanalysis, and environmental chemistry, impacting on the everyday life [1].
However, research on such systems is most often dominated by trial and error procedures, while a deep atomistic understanding of the phenomena inside the junction region driving appropriate design of the final device is missing. Here, a concerted theoretical and electrochemical investigation is proposed to gain insights into the important class of heterojunctions made by metal-semiconductor interfaces.
The presented case of study is the silver/anatase hybrid nanocomposite, a very promising material for advanced sensing applications [2]. Considering that in most cases titania semiconductors are useless in electroanalysis and silver is subject to fouling and oxidation/passivation, such broad outcomes were totally unexpected. Specifically, Ag/TiO2 interfase provided the first photorenewable sensor device, pushing the limits in terms of accuracy, sensitivity, detection limits, and photoactivity [3]. Despite the ongoing research, a quantitative and comprehensive understanding of the physics behind this nanocomposite is still missing, thus preventing its full exploitation and the extension of the same paradigm to other systems and devices.
In particular, cyclic voltammetry and electrochemical impedance spectroscopy are used in combination with periodic plane-wave DFT calculations, giving comparable qualitative, but also quantitative results. We measure the exceptional electrochemical virtues of the Ag/TiO2 junction in terms of current densities and reproducibility, providing their explanation at the atomic-scale level and demonstrating how and why silver acts as a positive electrode [4]. We theoretically estimate the overall amount of electron transfer toward the semiconductor side of the interface at equilibrium and suitably designed electrochemical experiments strictly agree with the theoretical charge transfer estimates. Moreover, photoelectrochemical measurements and theoretical predictions show the unique permanent charge separation occurring in the device, possible because of the synergy of Ag and TiO2, which exploits in a favorable band alignment, in a smaller electron–hole recombination rate and in a reduced carrier mobility when electrons cross the metal–semiconductor interface. Finally, the hybrid material is proven to be extremely robust against aging, showing complete regeneration, even after one year [4].
[1] A.V. Emeline, V.N. Kuznetsov, V.K. Ryabchuk, N. Serpone, Environ. Sci. Pollut. Res. 19 (2012) 3666–3675.
[2] G. Soliveri, V. Pifferi, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, K. Sparnacci, L. Falciola, Analyst 140 (2015) 1486–1494.
[3] V. Pifferi, G. Soliveri, G. Panzarasa, G. Cappelletti, D. Meroni, L. Falciola, Anal. Bioanal. Chem. 408 (2016) 7339–7349.
[4] G. Di Liberto, V. Pifferi, L. Lo Presti, M. Ceotto, and L. Falciola, J. Phys. Chem. Lett. 8 (2017) 5372–5377
Photo-renewable engineered sensor based on silica, silver nanoparticles and titania
No full textElectrode surface passivation and fouling are important challenges in electroanalysis when using modified electrodes in complex matrices, especially in the biomedical and environmental fields [1-2].
In order to overcome such problems, the production of highly engineered ad hoc designed devices could provide really effective sensors [2]. In particular, a reliable and reusable sensor, that could be cleaned by a simple irradiation with UV or solar light, could be perfect for this purpose.
In this context, a three-layered transparent electrode, in which silver nanoparticles are embedded between a bottom silica and a top titania layer is developed [3-4]. Such structure confers to the device multifunctional properties which can be conveniently used in the detection and quantification of some neurotransmitters: dopamine, norepinephrine and serotonin.
The sensor is thoroughly investigated by structural, morphological and electrochemical characterizations in order to understand the role of each component with the aim to improve the robustness and efficiency of the electroanalytical system. In particular, the size distribution of silver nanoparticles, the device architecture and surface homogeneity are inspected by electron microscopy. As confirmed by X-ray diffraction the overlayer is made of anatase (the active polymorph of titanium dioxide), capable of photodegrading model contaminants. Furthermore, electrochemical techniques (cyclic voltammetry and electrochemical impedance spectroscopy) revealed that a highly ordered distribution of silver nanoparticles constitutes the active analytical core of the device, allowing easier electron transfer and better quantification of the analytes.
The system presents good sensing performances, reaching low detection limits even in the presence of typical interferents such as ascorbic and uric acids. Moreover, the titania photoactive top layer allows the complete recovery of the device performance in terms of sensitivity after a fast and simple UV-A cleaning step, affordable with different UV sources. In particular, three lamps (different in terms of power and wavelength) were tested, reaching the total removal of the contaminants in 10-15 minutes [5]. This “self-cleaning” property, combined with a remarkable resistance against aging and ease of use, allows to employ the sensor also for detection in real matrixes, such as liquor and serum.
ACKNOWLEDGEMENTS
The Authors would like to thank MIUR (Ministero dell’Istruzione, dell’Università e della Ricerca) for the fundings in the framework of the PRIN 2012 Project (20128ZZS2H)
REFERENCES
[1] C.M.A. Brett, Pure Appl. Chem. 73, 2001, pp 1969–1977.
[2] C.M. Welch, R.G. Compton, Anal. Bioanal. Chem. 384, 2006, pp 601–619.
[3] G. Maino, D. Meroni, V. Pifferi, L. Falciola, G. Soliveri, G. Cappelletti, S. Ardizzone, J. Nanoparticle Res. 15, 2013, pp 2087.
[4] G. Soliveri, V. Pifferi, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, K. Sparnacci, L. Falciola, Analyst 140, 2015, 1486-1494.
[5] V. Pifferi, G. Soliveri, G. Panzarasa, S. Ardizzone, G. Cappelletti, D. Meroni, L. Falciola, RSC Advances, 5, 2015, 71210-71214
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