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1.
Sommovigo M Ferretti A Venturi M Ceroni P Giardi C Denti G 《Inorganic chemistry》2002,41(5):1263-1271
A study of absorption spectra in the near-infrared (NIR) and visible (vis) regions of trinuclear Ru complexes containing pyrazine (pyz) as bridging ligand, trans-[(Ru(NH(3))(5)pyz)(2)Ru(NH(3))(4)](m+)(m = 6-9), is reported. The spectra were recorded on aqueous solutions containing the described species formed in situ by stoichiometric additions of a standard solution of Ce(SO(4))(2). They were interpreted in terms of a simple 5-orbital-3-parameter model which includes the effects of d-pi interaction and electronic correlation. The model is shown to account for the observed NIR-vis spectra of the complex ions. The 6+ parent species was synthesized by an improved literature method and fully characterized. The novel 8+ complex was also prepared and characterized. The 9+ ion was established to be slowly reduced by water, with dioxygen formation. Electrochemical (CV and DPV) studies were performed on the trinuclear 6+ complex, as well as on its constituent fragments [Ru(NH(3))(5)(pyz)](2+) and trans-[Ru(NH(3))(4)(pyz)(2)](2+). 相似文献
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V. Scognamiglio D. Raffi M. Lambreva G. Rea A. Tibuzzi G. Pezzotti U. Johanningmeier M. T. Giardi 《Analytical and bioanalytical chemistry》2009,394(4):1081-1087
The unicellular green alga Chlamydomonas reinhardtii is employed here for the setup of a biosensor demonstrator based on multibiomediators for the detection of herbicides. The
detection is based on the activity of photosystem II, the multienzymatic chlorophyll–protein complex located in the thylakoid
membrane that catalyzes the light-dependent photosynthetic primary charge separation and the electron transfer chain in cyanobacteria,
algae, and higher plants. Several C. reinhardtii mutants modified on the D1 photosystem II protein are generated by site-directed mutagenesis and experimentally tested for
the development of a biosensor revealing the modification of the fluorescence parameter (1 − V
J) in the presence of herbicides. The A250R, A250L, A251C, and I163N mutants are highly sensitive to the urea and triazine
herbicide classes; the newly generated F255N mutant is shown to be especially resistant to the class of urea. It follows that
the response of the multibiomediators is associated to a particular herbicide subclass and can be useful to monitor several
species of pollutants. 相似文献
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Stephen MT Hoke Gaoyang Liang A Irina Mutiu Julie Genereaux Christopher J Brandl 《BMC biochemistry》2007,8(1):16
Background
Spt7 is an integral component of the multi-subunit SAGA complex that is required for the expression of ~10% of yeast genes. Two forms of Spt7 have been identified, the second of which is truncated at its C-terminus and found in the SAGA-like (SLIK) complex. 相似文献4.
Real-time monitoring of graphene oxide reduction in acrylic printable composite inks 总被引:1,自引:0,他引:1
S. Porro R. Giardi A. Chiolerio 《Applied Physics A: Materials Science & Processing》2014,117(3):1289-1293
This work reports the electrical characterization of a water-based graphene oxide/acrylic composite material, which was directly inkjet printed to fabricate dissipative patterns. The graphene oxide filler, which is strongly hydrophilic due to its heavily oxygenated surface and can be readily dispersed in water, was reduced by UV irradiation during photo-curing of the polymeric matrix. The concurrent polymerization of the acrylic matrix and reduction of graphene oxide filler was demonstrated by real-time resistance measurements during UV light irradiation. The presence of graphene filler allowed decreasing the resistance of the pure polymeric matrix by nearly five orders of magnitude. This was explained by the fact that clusters of reduced graphene oxide inside the polymer matrix act as preferential pathways for the mobility of charge carriers, thus leading to an overall decrease of the material’s resistance. 相似文献
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Touloupakis E Boutopoulos C Buonasera K Zergioti I Giardi MT 《Analytical and bioanalytical chemistry》2012,402(10):3237-3244
One of the limits of current electrochemical biosensors is a lack of methods providing stable and highly efficient junctions
between biomaterial and solid-state devices. This paper shows how laser-induced forward transfer (LIFT) can enable efficient
electron transfer from photosynthetic biomaterial immobilized on screen-printed electrodes (SPE). The ideal pattern, in terms
of photocurrent signal of thylakoid droplets giving a stable response signal with a current intensity of approximately 335 ± 13 nA
for a thylakoid mass of 28 ± 4 ng, was selected. It is shown that the efficiency of energy production of a photosynthetic
system can be strongly enhanced by the LIFT process, as demonstrated by use of the technique to construct an efficient and
sensitive photosynthesis-based biosensor for detecting herbicides at nanomolar concentrations. 相似文献
6.
Viviana Scognamiglio Gianni Pezzotti Ittalo Pezzotti Juan Cano Katia Buonasera Daniela Giannini Maria Teresa Giardi 《Mikrochimica acta》2010,170(3-4):215-225
Biosensors are projected to find many applications due to their high selectivity and sensitivity, rapid reaction, economy and ease of handling in field measurements. Even though biosensors for a wide range of environmental pollutants have been extensively reported in the literature, the decision to develop a suitable biosensing system that can be approved by a regulatory perspective for environmental applications is fraught with technical issues. These issues mainly concern the biological recognition element, the physico-chemical transducer and the interfaces between the biological and the physical components, but also aspects of fluidics, electronics, and software for data processing. This article reviews methods together with a process to move biosensor technology from research laboratories to market, focusing as a case in point on challenges and possible opportunities in the development of photosynthetic-based biosensors for environmental applications. 相似文献
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Viviana Scognamiglio Italo Pezzotti Gianni Pezzotti Juan Cano Ivano Manfredonia Katia Buonasera Fabiana Arduini Danila Moscone Giuseppe Palleschi Maria Teresa Giardi 《Analytica chimica acta》2012
In this paper we propose the construction and application of a portable multi-purpose biosensor array for the simultaneous detection of a wide range of endocrine disruptor chemicals (EDCs), based on the recognition operated by various enzymes and microorganisms. The developed biosensor combines both electrochemical and optical transduction systems, in order to increase the number of chemical species which can be monitored. Considering to the maximum residue level (MRL) of contaminants established by the European Commission, the biosensor system was able to detect most of the chemicals analysed with very high sensitivity. In particular, atrazine and diuron were detected with a limit of detection of 0.5 nM, with an RSD% less than 5%; paraoxon and chlorpyrifos were revealed with a detection of 5 μM and 4.5 μM, respectively, with an RSD% less than 6%; catechol and bisphenol A were identified with a limit of detection of 1 μM and 35 μM respectively, with an RSD% less than 5%. 相似文献