RESUMO
In this study, using pure and copper-doped titanium dioxide (Cu-TiO2) nanostructures as the base matrix, enzyme-less label free myoglobin detection to identify acute myocardial infarction was performed and presented. The Cu-TiO2 nanomaterials were prepared using facile sol-gel method. In order to comprehend the morphologies, compositions, structural, optical, and electrochemical characteristics, the pure and Cu-TiO2 nanomaterials were investigated by several techniques which clearly revealed good crystallinity and high purity. To fabricate the enzyme-less label free biosensor, thick films of synthesized nanomaterials were applied to the surface of a pre-fabricated gold screen-printed electrode (Au-SPE), which serves as a working electrode to construct the myoglobin (Mb) biosensors. The interference study of the fabricated biosensor was also carried out with human serum albumin (HSA) and cytochrome c (cyt-c). Interestingly, the Cu-doped TiO2 nanomaterial-based Mb biosensor displayed a higher sensitivity of 61.51 µAcm-2/nM and a lower detection limit of 14 pM with a response time of less than 10 ms.
Assuntos
Técnicas Biossensoriais , Nanoestruturas , Humanos , Mioglobina , Cobre , Titânio/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodosRESUMO
In this article, we describe the fabrication and characterization of a sensor for acute myocardial infarction that detects myoglobin biomarkers using chromium (Cr)-doped zinc oxide (ZnO) nanoparticles (NPs). Pure and Cr-doped ZnO NPs (13 × 1017, 20 × 1017, and 32 × 1017 atoms/cm3 in the solid phase) were synthesized by a facile low-temperature sol-gel method. Synthesized NPs were examined for structure and morphological analysis using various techniques to confirm the successful formation of ZnO NPs. Zeta potential was measured in LB media at a negative value and increased with doping. XPS spectra confirmed the presence of oxygen deficiency in the synthesized material. To fabricate the sensor, synthesized NPs were screen-printed over a pre-fabricated gold-coated working electrode for electrochemical detection of myoglobin (Mb). Cr-doped ZnO NPs doped with 13 × 1017 Cr atomic/cm3 revealed the highest sensitivity of ~37.97 µA.cm-2nM-1 and limit of detection (LOD) of 0.15 nM for Mb with a response time of ≤10 ms. The interference study was carried out with cytochrome c (Cyt-c) due to its resemblance with Mb and human serum albumin (HSA) abundance in the blood and displayed distinct oxidation potential and current values for Mb. Cr-doped ZnO NP-based Mb biosensors showed 3 times higher sensitivity as compared to pure ZnO NP-based sensors.
Assuntos
Infarto do Miocárdio , Nanopartículas , Óxido de Zinco , Biomarcadores , Cromo , Humanos , Nanopartículas Metálicas , Infarto do Miocárdio/diagnóstico , Mioglobina , Nanopartículas/química , Zinco , Óxido de Zinco/químicaRESUMO
A label free electrochemical sensor based on pure titanium oxide and manganese (Mn)-doped titanium oxide (TiO2) nanoparticles are fabricated and characterized for the sensitive detection of myoglobin (Mb) levels to analyze the cardiovascular infarction. Pristine and Mn-doped TiO2 nanoparticles were synthesized via the sol-gel method and characterized in order to understand their structure, morphologies, composition and optical properties. The structural properties revealed that the pure- and doped-TiO2 nanoparticles possess different TiO2 planes. FTIR studies confirm the formation of metal oxide nanoparticles by exhibiting a well-defined peak in the range of 600-650 cm-1. The values of the optical band gap, estimated from UV-Vis spectroscopy, are decreased for the Mn-doped TiO2 nanoparticles. UV-Vis spectra in the presence of myoglobin (Mb) indicated interaction between the TiO2 nanoparticles and myoglobin. The SPE electrodes were then fabricated by printing powder film over the working electrode and tested for label-free electrochemical detection of myoglobin (Mb) in the concentration range of 0-15 nM Mb. The fabricated electrochemical sensor exhibited a high sensitivity of 100.40 µA-cm-2/nM with a lowest detection limit of 0.013 nM (0.22 ng/mL) and a response time of ≤10 ms for sample S3. An interference study with cyt-c and Human Serum Albumin (HSA) of the sensors show the selective response towards Mb in 1:1 mixture.
Assuntos
Manganês/química , Mioglobina/análise , Nanopartículas/química , Titânio/química , Biomarcadores/análise , Técnicas Eletroquímicas , Humanos , Infarto do Miocárdio/diagnósticoRESUMO
Lung cancer detection includes detection of a pattern formed by multiple volatile organic compounds. An individual material has limited selectivity and hence requires tailoring to improve the selectivity and sensing properties. An electronic nose (e-nose) is a concept/device that can help in achieving selectivity and specificity for multiple volatile organic compounds at the same time by using an array of sensors. In this paper, Co and Ni doping in tin oxide was used to investigate as a sensor material for e-nose development. These were synthesized using a sol-gel method and were characterized for structural, morphological, and elemental assessment using X-ray diffraction, field emission scanning electron microscopy, and Fourier transform infrared spectroscopy, which indicated the formation of the composite nanomaterial of SnO2. These synthesized materials were then used as a working electrode in the form of a screen-printed electrode to determine 1-propanol and isopropyl alcohol (IPA) sensing characteristics. Electrochemical characterization was done by cyclic voltammetry (CV) and electrochemical impedance spectroscopy. In the case of CV studies, well-defined and distinct redox peaks are observed at different potential values indicating the changes due to the dopants. Ni doping in SnO2 shows the highest sensitivity of 2.99 µA/ppb for isopropyl alcohol and 3.11 for 1-propanol, within the detection range. Furthermore, Co-SnO2 shows selectivity for IPA, while Ni-SnO2 is selective to 1-propanol against all other volatile compounds analyzed.