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This review covers applications of pristine and functionalized single-wall carbon nanotubes (SWCNTs) in nano-medicine, cultural heritage, and biosensors. The physicochemical properties of these engineered nanoparticles are similar to those of ultrafine components of airborne pollution (UF) and might have similar adverse effects. UF may impair cardiovascular autonomic control (inducing a high-risk condition for adverse cardiovascular effects), cause mammalian embryo toxicity, and increase geno-cytotoxic risk. SWCNTs coated with a biopolymer, for example polyethylenimine (PEI), become extremely biocompatible, hence are useful for in-vivo and in-vitro drug delivery and gene transfection. It is also possible to successfully immobilize a human enteric virus on PEI/SWCNT composites, suggesting application as a carrier in non-permissive media. The effectiveness of carbon nanostructured materials in the cleaning, restoration, and consolidation of deteriorated historical surfaces has been widely shown by the use of carbon nanomicelles to remove black dendritic crust from stone surfaces. The nanomicelles, here, have the twofold role of delivery and controlled release of the cleaning agents. The high biocompatibility of functionalized SWCNTs with enzymes and proteins is a fundamental feature used in the assembly of electrochemical biosensors. In particular, a third-generation protoporphyrin IX-based biosensor has been assembled for amperometric detection of nitrite, an environmental pollutant involved in the biodeterioration and black encrustation of historical surfaces.

In this critical review, new nanomaterials based on graphene (GN) are described, especially those used for the assembly of miniaturized electrochemical transducers. In particular, the physicochemical properties and mechanical features of few layers of graphene (FLGs) are described, as is their use for assembly of chemically modified sensors, biosensors, and immunosensors. The FLGs described here were functionalized by chemical treatment in solution, resulting in oxidized and/or reduced surfaces, edges, and sides. The presence of oxygenated functionality strongly affects the electrocatalysis and the electron-transfer properties of several molecular targets, not only in the solid phase (e.g. in field-effect transistors, FETs) but also in liquid matrices (chemically modified electrodes and biosensors). In addition, “green chemistry” reagents, for example ionic liquids (ILs) can be used for exfoliation and intercalation of graphene planes, to obtain stable and homogeneous nanodispersions. The assembled sensors, biosensors, and immunosensors are extremely useful for electrochemical detection of several electro-active targets of importance in food analysis, environmental monitoring, and clinical diagnosis. A detailed description of each analytical application has been given in this critical review and brief remarks on the emerging disciplines of nanomedicine and nanofoods are also discussed.

Summary Background A high incidence of erectile dysfunction (ED) among patients with obstructive sleep apnoea syndrome (OSAS) has been reported, with a strong correlation between obstructive sleep apnoea, ED, and quality of life (QOL), and it has been estimated that 10–60% of patients with OSAS suffer from ED. In this prospective randomised controlled trial, we investigated 82 men with ED consecutively who were referred to the outpatient clinic for sleep disorders and had severe OSAS (AHI> 30 events/h) without any other comorbidities as a possible cause of ED. The aim of this study was to evaluate and compare the efficacy of sildenafil vs. continuous positive airway pressure (CPAP) in men with ED and severe OSAS. Methods Eighty‐two patients were randomised to two main treatment groups: group 1 patients (n = 41) were treated with 100‐mg sildenafil 1 h before sexual intercourse without CPAP, and group 2 patients (n = 41 men) were treated with only nasal CPAP during night time sleep. Both groups were evaluated with the same questionnaires (International Index of Erectile Function‐EF domain; Sex Encounter Profile; Erectile Dysfunction Inventory Treatment Satisfaction) 12 weeks after treatment. Results In patients receiving sildenafil treatment, 58.2% of those who attempted sexual intercourses were successful compared to 30.4% in the CPAP group. The mean number of successful attempts per week was significantly higher in the sildenafil group compared with the CPAP group (2.9 vs. 1.7, respectively; p < 0.0001). The mean IIEF‐EF domain scores were significantly higher in the sildenafil group compared with the CPAP group (p < 0.0001). The overall satisfaction rate was 68% with sildenafil treatment and 29% with CPAP treatment. Conclusions This study confirms that severe OSAS is strongly associated with erectile dysfunction. CPAP and sildenafil (100 mg) are safe and effective therapies for OSAS‐related ED patients. In the present study sildenafil was more effective than CPAP in treating ED associated with OSAS, as indicated by a significantly higher rate of successful attempts at intercourse and higher IIEF‐EF domain scores. Our study, to date, is the only that has investigated sildenafil in patients with severe OSAS.

An electrochemical sensor for palytoxin (PlTX) detection, based on a strip of eight screen-printed electrodes connected to a cost-effective and portable apparatus, is reported. Sheep erythrocytes were used to test the palytoxin detector and degree of haemolysis was evaluated by measuring release of the cytosolic lactate dehydrogenase (LDH). Percentage haemolysis and, therefore, the amount of LDH measured, by use of NADH/pyruvate and appropriate electrochemical mediators, was correlated with the concentration of the toxin. Two different electrochemical approaches were investigated for evaluation of LDH release, but only one based on the use of a binary redox mediator sequence (phenazine methosulfate in conjugation with hexacyanoferrate(III)) proved useful for our purpose. After analytical and biochemical characterization, the sensor strip was used to measure palytoxin. Sheep blood and standard solutions of PlTX were left to react for two different incubation times (24 h or 4 h), resulting in working ranges of 7 × 10 −3 –0.02 ng mL −1 and 0.16–1.3 ng mL −1 , respectively. The specificity of the test for palytoxin was evaluated by use of ouabain, which acts in the same way as PlTX on the Na + /K + -ATPase pump. A cross-reactivity study, using high concentrations of other marine biotoxins was also conducted. Experiments to evaluate the matrix effect and recovery from mussels are discussed. Figure ᅟ

Acetylcholinesterase (ChE) sensor based on Prussian blue (PB) modified electrode was developed and tested for the detection of organophosphorus and carbamic pesticides. The signal of the sensor was generated in PB mediated oxidation of thiocholine recorded at+200 mv in DC mode. ChE from electric eel was immobilized by cross-linking with glutaraldehyde in the presence of bovine serum albumin (BSA) on the surface of screen-printed carbon electrode covered with PB and Nafion. The content of the surface layer (specific enzyme activity, Nafion and BSA amounts) was optimized to establish high and reliable response toward the substrate and ChE inhibitors. The ChE/PB sensor makes it possible to detect Aldicarb, Paraoxon and Parathion-Methyl with limits of detection 30, 10 and 5 ppb, respectively (incubation 10 min). The feasibility of practical application of the ChE/PB sensor developed for the monitoring of degradation of the pesticides in wine fermentation was shown. To diminish matrix interferences, the electrolysis of the grape juice with Al anode and evaporation of ethanol were suggested, however the procedures decrease the sensitivity of pesticide detection and stability of the sample tested.

Issue Title: Paper-based microfluidic devices for monitoring heavy metals/X-ray contrast media and artificial sweeteners in water/Electrochemical genosensors for detecting coeliac disease/X-ray microfluorescence imaging of cell wall mutants

The ultrafine (UF) component of airborne pollution may impair cardiovascular autonomic control, a high-risk condition for cardiovascular adverse events. Since engineered nanoparticles, such as single-walled carbon nanotubes (SWCNTs) share physicochemical properties with UF, they might have similar adverse effects. Aim of the study was to evaluate arterial baroreflex function (BRF) at baseline, 24 h after the first instillation, immediately before the second one, and 2 weeks later, in adult Wystar-Kyoto conscious rats undergoing two intratracheal instillations of SWCNT (eight rats) or phosphate buffer saline (PBS) (five rats) at 2-week interval. During each session, 30-min continuous recording of arterial pressure and pulse interval was performed by a telemetered catheter implanted in the abdominal aorta of the rats. BRF was studied by the sequence technique. SWCNTs dispersed in PBS (1 mg/ml) were administered immediately after sonication (1 μg/g body weight). A significant decrease in the number of baroreflex sequences (from 498 ± 27.1 at baseline to 287 ± 40.2 at the recording performed after 4 weeks; P < 0.05) was observed in SWCNT-instilled rats, whereas no significant change was detected in controls. These data suggest that SWCNTs may alter the BRF, thus affecting the autonomic cardiovascular control regulation.

This work investigates the behaviour of two alternative systems that model the crucial event involved in any ELISA test, i.e. the molecular recognition between an antigen and its specific antibody on a solid phase, and its measurement. Each approach is devised with the goal of making possible a single-step, separation and wash-free amperometric magneto-immunosensor. Magnetic particles (MBs) are used as support for the immobilization of rabbit IgGs that are recognized by the specific anti-rabbit IgG-HRP. The assay protocol is based on the use of a series of small “reservoirs” containing phosphate buffer, hydroquinone, anti-rabbit IgG-HRP and an appropriate amount of MB-rabbit IgG. After a brief incubation, the content of each “reservoir” is transferred to one of the wells of a 8-well magnetized-screen-printed electrode strip. The resulting MB-IgG-anti-IgG-HRP chain, is then concentrated on the working electrode surface for electrochemical measurement. Two different approaches to monitor this immunological reaction are investigated. The first one is based on the enzyme-channeling principle (ECP) and involves the use of a second enzyme, glucose oxidase (GOD), immobilized on the working electrode previously modified with Prussian Blue. Since the H 2 O 2 produced by GOD is the co-substrate of the HRP enzyme, glucose is added into the well and the current, generated by the residual H 2 O 2 , is measured. The second, more direct, approach is performed without exploiting ECP (no GOD enzyme), by adding H 2 O 2 into the well and measuring the current generated by the HRP product on a pristine screen-printed electrode. Both approaches yielded a typical sigmoidal binding curve, illustrating the discrimination between the signal produced by the immuno-bound HRP concentrated on the electrode surface, and the background signal due to HRP in the bulk solution. Figure Schematic representation of the single-step immunoassay: in the upper part, the content of the ‘reservoirs’ (containing MB-rabbit IgG, TPi, HQ and various concentration levels of anti-rabbit IgG-HRP) are transferred to an 8 well/sensor strip coupled with an special magnetic support which can draw the IMBs to the electrode surface; the lower part shows the two electrochemical approaches proposed to monitor the immunological reaction

In this critical review, new nanomaterials based on graphene (GN) are described, especially those used for the assembly of miniaturized electrochemical transducers. In particular, the physicochemical properties and mechanical features of few layers of graphene (FLGs) are described, as is their use for assembly of chemically modified sensors, biosensors, and immunosensors. The FLGs described here were functionalized by chemical treatment in solution, resulting in oxidized and/or reduced surfaces, edges, and sides. The presence of oxygenated functionality strongly affects the electrocatalysis and the electron-transfer properties of several molecular targets, not only in the solid phase (e.g. in field-effect transistors, FETs) but also in liquid matrices (chemically modified electrodes and biosensors). In addition, \"green chemistry\" reagents, for example ionic liquids (ILs) can be used for exfoliation and intercalation of graphene planes, to obtain stable and homogeneous nanodispersions. The assembled sensors, biosensors, and immunosensors are extremely useful for electrochemical detection of several electro-active targets of importance in food analysis, environmental monitoring, and clinical diagnosis. A detailed description of each analytical application has been given in this critical review and brief remarks on the emerging disciplines of nanomedicine and nanofoods are also discussed. Keywords Few layers of graphene * Oxidized graphene nanoribbons * Reduced graphene nanoribbons * Sensors * Biosensors * Immunosensors * Green chemistry and ionic liquids * Nanomedicine and nanofoods

This paper describes a direct competitive immunoenzymatic spectrophotometric assay (ELISA) for tetrodotoxin (TTX) determination and the adaptation of this method for use in an electrochemical assay format. The novelty of this work involves the use of the antigen labelled with alkaline phosphatase (AP); this conjugate was prepared in our laboratory as there is no commercially available conjugate of any kind for TTX. The new conjugate was characterized in terms of its affinity for the specific antibody as well as the residual concentration and the residual activity of the enzyme (AP) incorporated as label. The proposed method based on the new conjugate showed satisfactory results for TTX determination: for the spectrophotometric method the dynamic range was 4-15 ng mL-¹ with a limit of detection (LOD) of 2 ng mL-¹ (R=0.9247), whereas for the electrochemical protocol the dynamic range was 2-50 ng mL-¹ and the LOD was1 ng mL-¹.