Synergy effect of nanocrystalline cellulose for the biosensing detection of glucose

Integrating polypyrrole-cellulose nanocrystal-based composites with glucose oxidase (GOx) as a new sensing regime was investigated. Polypyrrole-cellulose nanocrystal (PPy-CNC)-based composite as a novel immobilization membrane with unique physicochemical properties was found to enhance biosensor performance. Field emission scanning electron microscopy (FESEM) images showed that fibers were nanosized and porous, which is appropriate for accommodating enzymes and increasing electron transfer kinetics. The voltammetric results showed that the native structure and biocatalytic activity of GOx immobilized on the PPy-CNC nanocomposite remained and exhibited a high sensitivity (ca. 0.73 μA·mM−1), with a high dynamic response ranging from 1.0 to 20 mM glucose. The modified glucose biosensor exhibits a limit of detection (LOD) of (50 ± 10) µM and also excludes interfering species, such as ascorbic acid, uric acid, and cholesterol, which makes this sensor suitable for glucose determination in real samples. This sensor displays an acceptable reproducibility and stability over time. The current response was maintained over 95% of the initial value after 17 days, and the current difference measurement obtained using different electrodes provided a relative standard deviation (RSD) of 4.47%

Non- Pharmacological Approaches on the Improvement of Sleep Disturbances in Patients with Autism Spectrum Disorder (ASD)

Objective Autism is a type of neurodegenerative disorder, affected by genetic and environmental factors. Children with autism spectrum disorder (ASD) have symptoms of attention deficit and behavioral problems. The amount of sleep has a significant effect on a child's mood. Sleep problems in a child with autism are more common than a normal child. The aim of this study was to investigate the effect of non- pharmacological approaches on the improvement of sleep disturbances in patients with ASD. Materials & Methods PubMed, EMBASE, Web of Science, Scopus, and Science Direct databases were systematically searched for articles published between January 2009 and May 2019. All original articles from observational and interventional studies were reviewed. The CONSORT Statement and Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist were used to assess the quality of the selected papers. Results  A review of 18 eligible articles according to the CONSORT checklist (for interventional studies) and STROBE (for descriptive studies) demonstrated that behavioral interventions, such as cognitive-behavioral therapy, bedtime fading with response cost, and functional behavioral assessment, physical activity such as aerobic exercise, swimming, and aquatic exercise and weighted blankets could be effective in the improvement of sleep disturbances. Conclusion Restlessness, tantrum, increased stereotypic activities, reduced learning level and speaking power in children with autism was due to poor sleep quality and sleep deficiency, which could affect their life dimensions. Non- pharmacological approaches to the treatment of sleep disturbances could improve both the sleep quality of these individuals and the quality of their lives in addition to having no adverse effect.     &nbsp

Surface plasmon resonance detection of copper corrosion in biodiesel using polypyrrole-chitosan layer sensor

Copper corrosion is one of the important parameters used for evaluating the quality of biodiesel. In this work, a polypyrrole-chitosan sensing layer was utilized for the detection of Cu2+ in biodiesel using the surface plasmon resonance technique. With the sensitivity of this sensor being about 0.1 ppm, different corrosion levels could be recognized in samples that were classified as class 1a according to the standard copper strip test

The Effect of Guided Imagery and Music on the Level of Sexual Satisfaction of Women of Reproductive Age: A parallel cluster- Randomized Trial

Background & aim: As one of the most influential factors of marital life, sexual satisfaction can significantly lead to peace and compatibility of couples. The present study investigated the effect of Guided Imagery and Music (GIM) on the level of sexual satisfaction in women of reproductive age.Methods: In this parallel cluster-randomized trial which was conducted from Feb. 2019 to Apr. 2020, 72 women of reproductive age (two groups of 36 subjects) who had moderate or undesirable sexual satisfaction were sampled. The guided imagery music was presented for the intervention group for 6 weeks as twice a week. No intervention was performed for the control group.  The data collection tool included fertility characteristics and Larson questionnaires, which was completed before, immediately and one month after the intervention. Data were analyzed by SPSS software (version 20) using independent t-test, chi-square, Mann-Whitney and variance analysis with repeated measurements.Results:  There was no statistically significant difference between the two groups in the sexual satisfaction score before the intervention. The mean sexual satisfaction score in the intervention group had a statistically significant difference between the baseline (91.1±9.1), immediately after intervention (112±4.46) and one month later (102±9.24) (P< 0.001). However, there was no significant difference between the changes in the sexual satisfaction of women in the control group between three times.Conclusion: GIM technique improves women's sexual satisfaction. It is recommended to health care providers to use this behavioral technique to enhance the level of sexual satisfaction in women of reproductive age

Polypyrrole thin film sensor base surface plasmon resonance for detection of Cu(II) and Fe(III) in aqueous solution

In this study, the performance of surface plasmon resonance method incorporated with polypyrrole sensing layer was examined for detection of Cu (II) and Fe (III) ions in aqueous solutions. The polypyrrole was prepared by electro-oxidation method on a gold layer for the detecting low concentration ions (0.1, 1 5 10 20 ppm). The experiments carried out at room temperature, and each sample was flowed through the flow cell. A photodiode registered the SPR signals as the function of rotation angle and thickness of layers. For observing the association and dissociation processes, the experiments repeated more than ten times, and the sensorgrams were obtained. Furthermore, Langmuir model was utilized to describe the binding interactions of ions with the polypyrrole layer. The lower concentration detection limit was about 0.1 ppm and the terminal resonance angles were occurred after the 300 s. The sensor was also found to be more sensitive to the presence of Cu than Fe ions

Synthesis and application of polypyrrole/carrageenan nano-bio composite as a cathode catalyst in microbial fuel cells

A novel nano-bio composite polypyrrole (PPy)/kappa-carrageenan(KC) was fabricated and characterized for application as a cathode catalyst in a microbial fuel cell (MFC). High resolution SEM and TEM verified the bud-like shape and uniform distribution of the PPy in the KC matrix. X-ray diffraction (XRD) has approved the amorphous structure of the PPy/KC as well. The PPy/KC nano-bio composites were then studied as an electrode material, due to their oxygen reduction reaction (ORR) ability as the cathode catalyst in the MFC and the results were compared with platinum (Pt) as the most common cathode catalyst. The produced power density of the PPy/KC was 72.1 mW/m2 while it was 46.8 mW/m2 and 28.8 mW/m2 for KC and PPy individually. The efficiency of the PPy/KC electrode system is slightly lower than a Pt electrode (79.9 mW/m2) but due to the high cost of Pt electrodes, the PPy/KC electrode system has potential to be an alternative electrode system for MFCs

Conducting polymer composite based on nano-cellulose for biosensing application

Application of conducting polymers of polypyrrole and polyaniline-cellulose nanocrystal based composite as electron-transfer pathways in enzyme electrodes was investigated. Polypyrrole-cellulose nanocrystal (PPy-CNC)-based composite as a novel immobilization membrane was prepared by chemical polymerization. Modified electrodes were prepared based on drop casting of nanocomposite suspension on the screen printed electrode (SPE) surface following by GOx immobilization. Field emission scanning electron microscopy (FESEM) images showed the porous structure of the nanocomposite with large surface area which could accommodate a large quantity of enzyme and allow the rapid diffusion of the active enzyme into the sensing membrane. The electrochemical and DPV responses of the GOx for glucose biosensor detection were examined in detail. The anodic current (Ip) in the voltammogram of the modified electrode prepared from PPy-CNC showed higher value compare to modified electrode prepared from pure polymer indicating CNC enhanced electron transferring and biosensor performance. The modified glucose biosensor exhibits a high sensitivity (ca. 0.73 μA.mM−1), with a dynamic response ranging from 1.0 to 20 mM glucose. The modified glucose biosensor exhibits a limit of detection (LOD) of (50±10) μM and also excludes interfering species, such as ascorbic acid, uric acid, and cholesterol, which makes this sensor suitable for glucose determination in real samples. This sensor displays an acceptable reproducibility and stability over time. The current response was maintained over 95% of the initial value after 17 days, and the current difference measurement obtained using different electrodes provided a relative standard deviation (RSD) of 4.47%

One-step electrochemical deposition of PolypyrroleChitosanIron oxide nanocomposite films for non-enzymatic glucose biosensor

One-step electrodeposition method of Polypyrrole–Chitosan–Iron oxide (Ppy–CS–Fe3O4) nanocomposite films (Ppy–CS–Fe3O4NP/ITO) has been developed for the fabrication of advanced composite coatings for biosensors applications. The FESEM and EDX results provide the evidence of successful incorporation of Fe3O4 into Ppy–CS molecules. The presence of Fe3O4 nanoparticles in the nanocomposite films was further confirmed by the XRD and XPS spectrums. The fabricated electrode Ppy–CS–Fe3O4 NP/ITO shows a fast amperometric response with high selectivity to detect glucose non-enzymatically with improved linearity (1–16 mM) and the detection limit of (234 μM) at a signal-to-noise ratio (S/N=3.0)

Polyaniline-modified nanocellulose prepared from Semantan bamboo by chemical polymerization: preparation and characterization

Crystalline nanocellulose was prepared from Semantan bamboo (Gigantochloa scortechinii) via acid hydrolysis and was used to synthesize a nanocomposite of polyaniline/crystalline nanocellulose (PANi/CNC) via in situ oxidative polymerization of aniline in the presence of crystalline nanocellulose. The electrochemical properties of the nanocomposite were studied using a modified PANi/CNC electrode via cyclic voltammetry, and higher current response was observed for the PANi/CNC-modified electrode compared to that for the modified electrode with PANi. The results obtained from EIS displayed lower value of Rct for the PANi/CNC-modified electrode, indicating that the incorporation of CNC into the PANi structure could enhance the electron transfer rate. The characteristic peaks of PANi and CNC were observed in the FTIR spectra of the nanocomposite, indicating the incorporation of CNC inside the nanocomposite structure. Moreover, in the XRD diffractogram, lower crystallinity was observed at the 2 theta values of 22.6 and 16.1 for PANi/CNC compared to that for pure CNC. The FESEM images showed high porosity of the nanostructure with no phase separation, revealing the homogenous polymerization of the monomer on the surface of the crystalline cellulose. Aggregation of PANi particles was observed with the increasing aniline concentration