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Percorrer por autor "Moreira, Beatriz Oliveira"

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  • Bioinspired electrochemical platform for detection of inflammation-related biomarkers
    Publication . Moreira, Beatriz Oliveira; Marques, Maria Arcelina
    An adaptive reaction known as inflammation is typically brought on by unpleasant stimuli and diseases such as widespread infection and/or tissue damage. The immune system launches an inflammatory reaction as a defensive strategy, producing cells and cytokines to combat these invaders, which may cause discomfort, redness, swelling, and bruising. In particular, the liver produces the biomolecule C-Reactive Protein (CRP) in reaction to cytokines that are generated during inflammatory and infectious processes. In this situation, the creation of straightforward, affordable, and user-friendly diagnostic instruments to check for inflammatory biomarkers at the point of treatment might be very beneficial for therapeutic purposes. The goal of this research is to create an electrochemical biosensor with exceptional sensitivity that can monitor CRP. The molecularly imprinted polymer (MIP), which serves as the biorecognition component of the biosensor, is formed by electrochemically polymerizing a combination of aniline and chitosan in the presence of the target protein, CRP. Here, adding chitosan to the monomer mixture significantly improves the biosensor's stability and repeatability. The bulk technique, which offers a straightforward, quick, one-step procedure for altering and assessing various variables, was used to assemble the polymeric film by means of electropolymerization. It is feasible to model and control the thickness and porosity of the produced polymeric film by changing and adjusting electropolymerization process parameters including the scanning rate and the number of cycles. The scanning speed chosen for the studies was 0.5 Vs-1 and the number of electropolymerization cycles optimised was 5 cycles. After electrochemical synthesis, CRP was successfully removed from the polymeric network using acidorganic combinations, allowing cavities that are complementary in size and shape to the target molecule to develop. Electrochemical impedance spectroscopy (EIS) was used to assess the electrochemical performance while the biosensor assembly was being optimized. The imprinting effect was subsequently demonstrated by examining the electrochemical detection properties, and the improved biosensor showed a linear electrochemical response in the concentration range of 0.001 ng mL -1 to 0.01 µg mL -1 and a LOD of 2.22 pg mL-1 . Furthermore, surface alterations on the gold electrode were validated by chemical and morphological characterizations like Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and Raman techniques. In terms of sensitivity, stability, and repeatability, the final biosensor device showed significant promise, making it a more convenient and affordable alternative for monitoring chronic wounds progression.
    2023Dissertação de mestrado Acesso aberto Ver mais