Herein the development of an alternative optic-conductive fiber configuration applied for the construction of biosensing platforms. This new approach is based on applying the chemical polymerization of pyrrole onto the surface of polymethyl metacrylate (PMMA) fibers to create a polymer--a conductive surface, onto which an additional photoactive polypyrrole-benzophenone (PpyBz) film is electrochemically generated upon the fiber surface. Irradiation of the benzophenone groups embedded in the Ppy films with UV radiation (350 nm) formed active radicals that allowed the covalent attachment of the desired bioreceptors. Characterization of the amperometric biosensing matrix was accomplished by using a model Urease (Urs) through electrochemical impedance spectroscopy (EIS) and amperometry. Both techniques have shown a low charge transfer resistance (340 k Omega) and a high sensitivity (12.3 microA mM(-1)cm(-2)). Thereafter, the construction of an optical biosensing matrix based on horseradish peroxidase (HRP) production of photons was carried out. The high signal to noise (S/N) ratio (1600) indicated clearly that this approach can serve as a new platform to replace glass optical fibers based on biosensors.
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http://dx.doi.org/10.1016/j.bios.2009.04.035 | DOI Listing |
Molecules
December 2024
Dipartimento di Chimica e Biologia, and INSTM Research Unit, Università di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, SA, Italy.
Plastic pollution is a global problem affecting the environment and, consequently, people's well-being. Careful and timely end-of-life plastic recycling is certainly a way, albeit a partial one, to remedy the problem. The immediate identification and selection of the different types of plastic materials in the recycling process certainly facilitate its recovery and reuse, allowing the damage caused by plastic emission into the environment to be limited.
View Article and Find Full Text PDFJ Adv Prosthodont
April 2024
Department of Prosthodontics, Faculty of Dentistry, Ankara Yıldırım Beyazıt University, Ankara, Türkiye.
Purpose: The purpose of this study was to investigate the fracture resistance, surface hardness, and color stain of 3D printed, CAD-CAM milled, and conventional interim materials.
Materials And Methods: A total of 80 specimens were fabricated from auto polymerizing polymethyl methacrylate (PMMA), bis-acryl composite resin, CAD-CAM polymethyl methacrylate resin (milled), and 3D printed composite resin (printed) (n = 20). Forty of them were crown-shaped, on which fracture strength test was performed (n = 10).
J Adv Prosthodont
October 2023
Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry - University of Sao Paulo, Ribeirão Preto, SP, Brazil.
Purpose: This study aimed to assess and compare the color stability, flexural strength (FS), and surface roughness of occlusal splints fabricated from heat-cured acrylic resin, milled polymethyl methacrylate (PMMA)-based resin, and 3D-printed (PMMA) based-resin.
Materials And Methods: Samples of each type of resin were obtained, and baseline measurements of color and surface roughness were recorded. The specimens were divided into three groups (n = 10) and subjected to distinct aging protocols: thermomechanical cycling (TMC), simulated brushing (SB), and control (without aging).
Ultrasonics
September 2023
Montpellier University, IES, UMR 5214, 860 rue Saint Priest, 34090, France; CNRS, IES, UMR 5214, Montpellier University, 860 rue Saint Priest, 34090, France.
PMMA is often considered as a calibration material for experimental benches dedicated to viscoelasticity investigation. Nevertheless, regarding literature, data concerning attenuation coefficients and quality factors are essentially available in the MHz frequency range and results in the low-frequency range are scarce and scattered. In this communication, thanks to the use of high-frequency ultrasonic spectroscopy between 2 and 8 MHz in the range 6 °C - 45 °C, Time-Temperature Superposition principle and Resonant Ultrasonic Spectroscopy (RUS), we show that both longitudinal and shear quality factors of PMMA decrease considerably for low frequencies (
Medicine (Baltimore)
February 2023
Division of Plastic and Reconstructive Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
Rationale: Cranioplasty is a surgical procedure used to repair cranial defects for both cosmetic and functional reasons. The complication rate of cranioplasty is between 10% and 50%. The failure of cranioplasty is associated with various factors, including etiologies, types of material, and the timing of cranioplasty.
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