The role of volume hydrogel holographic gratings as optical transducers in sensor devices for point-of-care applications is increasing due to their ability to be functionalized for achieving enhanced selectivity. The first step in the development of these transducers is the optimization of the holographic recording process. The optimization aims at achieving gratings with reproducible diffraction efficiency, which remains stable after reiterative washings, typically required when working with analytes of a biological nature or several step tests.
View Article and Find Full Text PDFThe present research is focused on the development of a biofunctionalized hydrogel with a surface diffractive micropattern as a label-free biosensing platform. The biosensors described in this paper were fabricated with a holographic recording of polyethylene terephthalate (PET) surface micro-structures, which were then transferred into a hydrogel material. Acrylamide-based hydrogels were obtained with free radical polymerization, and propargyl acrylate was added as a comonomer, which allowed for covalent immobilization of thiolated oligonucleotide probes into the hydrogel network, via thiol-yne photoclick chemistry.
View Article and Find Full Text PDFThe storage of time-stable holographic gratings in hydrogel matrices when the material is immersed in aqueous media is a real challenge at present. The optimization of the storage stages of the holograms must be properly investigated to identify the most suitable development processes. For this reason, this work is focused on the study of the optimization of the washing stages of the hydrogels based on acrylamide and ,'-methylenebis(acrylamide) once unslanted transmission holograms have been stored.
View Article and Find Full Text PDFAnalyte-sensitive DNA-based hydrogels find multiple applications in the field of biosensors due to their adaptable nature. Here, the design of DNA-based hydrogel and its application as sensing platform for the detection of a specific target sequence are presented. DNA-functionalized hydrogel structures were formed via a free radical co-polymerization process.
View Article and Find Full Text PDFElectrospun fibers of shape memory triethoxysilane-terminated poly(epsilon-caprolactone) (PCL-TES) loaded with bioactive glasses (BG) are here presented. Unloaded PCL-TES, as well as PCL/BG nanocomposite fibers, are also considered for comparison. It is proposed that hydrolysis and condensation reactions take place between triethoxysilane groups of the polymer and the silanol groups at the BG particle surface, thus generating additional crosslinking points with respect to those present in the PCL-TES system.
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