RESUMO
BACKGROUND: Mobile-linked point-of-care diagnostics forms an integral part of diagnostic health services for efficient communication between patients and healthcare professionals despite geographical location and time of diagnosis. The efficiency of this technology lies in the user experience which means that the interaction of the user with the implemented technology needs to be simple, convenient, and consistent. Having a well-structured user experience of these devices in community-based healthcare will aid in sustainable implementation. Herein, we propose to conduct a literature search to systematically map out evidence based on mobile-linked POC diagnostics user experience at a community level in resource-limited settings. METHODOLOGY: The proposed scoping review will be guided by the advanced Arksey and O'Malley methodological framework and further advanced by Levac et al. A comprehensive search will be conducted to find relevant published literature from the following electronic databases: Scopus, Web of Science, EBSCOhost (Medline, CINAHL, Africa-wide, Academic Search Complete). Grey literature will also be searched, including reports from government and international organizations such as World Health Organization (WHO), Foundation for Innovative New Diagnostics (FIND), and the Food and Drug Administration (FDA). Two independent reviewers will screen the relevant studies and the degree of the agreement will be determined by calculating Cohen's kappa statistic. The quality of eligible data will also be appraised using the mixed method appraisal tool version 2018. DISCUSSION: We anticipate that the planned scoping review will present useful evidence to inform stakeholders on the integration of mobile-linked diagnostic devices in community-based healthcare which will guide further research on the subject.
Assuntos
Serviços de Saúde Comunitária , Testes Imediatos , Humanos , África , Organização Mundial da Saúde , Atenção à Saúde/métodos , Literatura de Revisão como AssuntoRESUMO
Prostate specific antigen (PSA) aptasensors are fabricated using a novel asymmetrically substituted Co phthalocyanine (CoPc), gold nanoparticles (AuNPs) and PSA-specific antigen. The fabricated aptasensors are: GCE-AuNPs-Aptamer, GCE@CoPc-Aptamer and GCE-AuNPs@CoPc-Aptamer (GCE = glassy carbon electrode). The fabricated sensors are characterized at each modification step to monitor the changes occurring at the sensor surface. Concentration studies were carried out using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) to determine detection limits. All the fabricated aptasensors were found to be highly specific and selective but the GCE-AuNPs@CoPc-Aptamer nanoconjugate performed the best. The aptasensors were also tested in spiked serum samples and detection limits, as well as % recoveries were determined. The results obtained showed that the GCE-AuNPs@CoPc-Aptamer has the potential to be used for clinical studies as the results agree with those obtained for detection of PSA in buffer.
Assuntos
Aptâmeros de Nucleotídeos , Nanopartículas Metálicas , Técnicas Eletroquímicas , Ouro , Humanos , Isoindóis , Masculino , Antígeno Prostático EspecíficoRESUMO
Herein, a novel aptasensor is developed for the electrochemical detection of prostate specific antigen (PSA) on electrode surfaces modified using various combinations of a Cobalt phthalocyanine (CoPc), an aptamer and graphene quantum dots (GQDs). Electrochemical impedance spectroscopy (EIS) as well as differential pulse voltammetry (DPV) are employed for the detection of PSA. In both analytical techniques, linear calibration curves were observed at a concentration range of 1.2-2.0 pM. The glassy carbon electrode where CoPc and GQDs are placed on the electrode when non-covalently linked followed by addition of the aptamer (GQDs-CoPc(ππ)-aptamer (sequential)) showed the best performance with a limit of detection (LoD) as low as 0.66 pM when using DPV. The detection limits were much lower than the dangerous levels reported for PSA in males tested for prostate cancer. This electrode showed selectivity for PSA in the presence of bovine serum albumin, glucose and L-cysteine. The aptasensor showed good stability, reproducibility and repeatability, deeming it a promising early detection device for prostate cancer.
Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Grafite/química , Indóis/química , Compostos Organometálicos/química , Antígeno Prostático Específico/análise , Pontos Quânticos/química , Técnicas Biossensoriais/instrumentação , Carbono/química , Espectroscopia Dielétrica , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Limite de Detecção , Antígeno Prostático Específico/química , Reprodutibilidade dos TestesRESUMO
In this work, we characterized different phtalocyanine-capped core/shell/shell quantum dots (QDs) in terms of stability, ζ-potential, and size at various pH and ionic strengths, by means of capillary electrophoresis (CE), and compared these results to the ones obtained by laser Doppler electrophoresis (LDE) and dynamic light scattering (DLS). The effect of the phthalocyanine metallic center (Zn, Al, or In), the number (one or four), and nature of substituents (carboxyphenoxy- or sulfonated-) of functionalization on the phthalocyanine physicochemical properties were evaluated. Whereas QDs capped with zinc mono-carboxyphenoxy-phtalocyanine (ZnMCPPc-QDs) remained aggregated in the whole analyzed pH range, even at low ionic strength, QDs capped with zinc tetracarboxyphenoxy phtalocyanine (ZnTPPc-QDs) were easily dispersed in buffers at pH equal to or higher than 7.4. QDs capped with aluminum tetrasulfonated phthalocyanine (AlTSPPc-QDs) and indium tetracarboxyphenoxy phthalocyanines (InTCPPc-QDs) were stable in aqueous suspension only at pH higher than 9.0 due to the presence of functional groups bound to the metallic center of the phthalocyanine. The ζ-potential values determined by CE for all the samples decreased when ionic strength increased, being well correlated with the aggregation of the nanoconjugates at elevated salt concentrations. The use of electrokinetic methodologies has provided insights into the colloidal stability of the photosensitizer-functionalized QDs in physiological relevant solutions and thereby, its usefulness for improving their design and applications for photodynamic therapy. Graphical Abstract Schematic illustration of the phthalocyanine capped QDs nanoconjugates and the capillary electrophoresis methods applied for size and ζ-potential characterization.