Browsing by Author "Correia, Bárbara P."
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- Development of colorimetric cellulose-based test-strip for the rapid detection of antibodies against SARS-CoV2 virusPublication . Correia, Bárbara P.; Sousa, Mariana P.; Sousa, Cristina E. A.; Mateus, Daniela; Sebastião, Ana Isabel; Cruz, Maria Teresa; Matos, Ana Miguel; Santos Pereira, Ana Cláudia; Moreira, FelisminaGiven the pandemic situation, there is an urgent need for an accurate test to monitor antibodies anti-SARS-CoV-2, providing crucial epidemiological and clinical information to monitor the evolution of coronavirus disease in 2019 (COVID-19) and to stratify the immunized and asymptomatic population. Therefore, this paper describes a new cellulosebased test strip for rapid and cost-efective quantitative detection of antibodies to SARS-CoV2 virus by colorimetric transduction. For this purpose, Whatman paper was chemically modifed with sodium metaperiodate to introduce aldehyde groups on its surface. Subsequently, the spike protein of the virus is covalently bound by forming an imine group. The chemical control of cellulose paper modifcation was evaluated by Fourier transform infrared spectroscopy, thermogravimetry and contact angle analysis. Colorimetric detection of the antibodies was performed by a conventional staining method using Ponceau S solution as the dye. Color analysis was performed after image acquisition with a smartphone using Image J software. The color intensity varied linearly with the logarithm of the anti-S concentration (from 10 ng/mL to 1 μg/mL) in 500-fold diluted serum samples when plotted against the green coordinate extracted from digital images. The test strip was selective in the presence of nucleocapsid antibodies, urea, glucose, and bovine serum albumin with less than 15% interference, and detection of antibodies in human serum was successfully performed. Overall, this is a simple and afordable design that can be readily used for mass Abstract Given the pandemic situation, there is an population screening and does not require sophisticated equipment or qualifed personnel
- Transdermal electrochemical sensing: Combining microneedles with molecularly imprinted polymers for point-of-care testingPublication . Oliveira, Daniela; Correia, Bárbara P.; Sharma, Sanjiv; Moreira, Felismina T.C.Biomarkers from interstitial skin fluid (ISF) complement conventional biofluids for point-of-care testing and real-time monitoring. In this study, we propose a new approach that combines microneedle technology with molecularly imprinted polymers to improve transdermal electrochemical sensing. The molecularly imprinted polymer, which acts like a plastic antibody, is easy to synthesis and scalable, offering a low detection limit and rapid measurement (20 minutes). It detects IL -6, a proinflammatory cytokine associated with several clinical conditions, including neurological disease and pneumonia caused by SARS-CoV-2. The transdermal sensors successfully identified IL -6 in simulated skin ISF at very low concentrations (1 pg/mL). This breakthrough enables affordable and bloodless testing, facilitating access to point-of-care testing worldwide. The integration of molecularly imprinted polymers and microneedle arrays is very promising for efficient transdermal electrochemical sensing that could find application in various clinical scenarios.