In this study, PQQ-dependent glucose dehydrogenase (PQQ-GDH) was immobilized onto reduced graphene oxide (rGO) modified with organic dyes from three different classes (acridine, arylmethane, and diazo); namely, neutral red (NR), malachite green (MG), and congo red (CR) formed three types of biosensors. All three rGO/organic dye composites were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The impact of three rGO/organic dye modifications employed in bioelectrocatalytic systems on changes in enzyme activity and substrate selectivity was investigated.
View Article and Find Full Text PDFAceclofenac (ACL) is an anti-inflammatory drug, which is taken by patients who mainly suffer from rheumatoid conditions. In this work, we propose a new voltammetric method that allows the determination of ACL in pharmaceutics, urine, and plasma. As a working electrode, a glassy carbon electrode (GCE) modified with carbon nanofibers, carbon nanotubes, and NiCo nanoparticles (eCNF/CNT/NiCo-GCE) was used.
View Article and Find Full Text PDFThe control of glucose concentration is a crucial factor in clinical diagnosis and the food industry. Electrochemical biosensors based on reduced graphene oxide (rGO) and conducting polymers have a high potential for practical application. A novel thermal reduction protocol of graphene oxide (GO) in the presence of malonic acid was applied for the synthesis of rGO.
View Article and Find Full Text PDFThe melt of H₃BO₃ was used to reach a controllable reduced graphene oxide (rGO) synthesis protocol using a graphene oxide (GO) precursor. Thermogravimetric analysis and differential scanning calorimetry (TG/DSC) investigation and scanning electron microscopy (SEM) images have shown that different from GO powder, reduction of GO in the melt of H₃BO₃ leads to the formation of less disordered structure of basal graphene planes. Threefold coordinated boron atom acts as a scavenger of oxygen atoms during the process of GO reduction.
View Article and Find Full Text PDFThe nanocomposite coatings made using graphene oxide (GO) and six different organic dyes were used to produce the laser-induced graphene (LIG) coatings by means of near infrared picosecond laser irradiation. The coatings were investigated by means of contact angle measurement with three liquids (1-bromonaphtalene, glycerol and water), Raman spectroscopy, scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis. It was found that the more hydrophilic is the precursor surface the more hydrophobic LIG surface is produced after the laser treatment.
View Article and Find Full Text PDFAiming to create reagentless amperometric D-fructose biosensor, graphene based electrode materials have been synthesized by newly proposed thermal reduction of graphene oxide. The method allowed to separate and collect different fractions of thermally reduced graphene oxide (TRGO) with different physicochemical properties. The structural characteristics and surface morphologies of TRGO fractions were evaluated using SEM, XRD, TGA analysis, Raman spectroscopy and BET measurements.
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