Browsing by Author "Barcelay, Yonny Romaguera"
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- An electrochemically synthesized molecularly imprinted polymer for highly selective detection of breast cancer biomarker CA 15-3: a promising point-of-care biosensorPublication . Oliveira, Daniela; Barcelay, Yonny Romaguera; Moreira, Felismina T. C.In this study, a molecularly imprinted polymer film (MIP) was prepared on the surface of a disposable carbon screen-printed electrode (C-SPE) using (3-acrylamidopropyl)trimethylammonium chloride (AMPTMA) as a functional monomer and the cancer biomarker carbohydrate antigen 15-3 (CA 15-3) as a template. The MIP was synthesized by in situ electropolymerization (ELP) of the AMPTMA monomer in the presence of the CA 15-3 protein on the C-SPE surface. The target was subsequently removed from the polymer matrix by the action of proteinase K, resulting in imprinted cavities with a high affinity for CA 15-3. Electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the different phases of the sensor assembly. Chemical and morphological analysis was performed using RAMAN and scanning electron microscopy (SEM). CA 15-3 was successfully detected in a wide working range from 0.001 U mL−1 to 100 U mL−1 with a correlation coefficient (R2) of 0.994 in 20 min. The MIP sensor showed minimal interference with other cancer proteins (CEA and CA 125). Overall, the developed device provides a rapid, sensitive, and cost-effective response in the detection of CA 15-3. Importantly, this comprehensive approach appears suitable for point-of-care (PoC) use, particularly in a clinical context.
- Liquid Redox Probe-Free Plastic Antibody Development for Malaria Biomarker RecognitionPublication . Glória, Juliane Corrêa; Oliveira, Daniela S.; Gandarilla, Ariamna Dip; Barcelay, Yonny Romaguera; Mariúba, Luis André Morais; Nogueira, Paulo Afonso; Brito, Walter Ricardo; Moreira, Felismina T. C.; Moreira, Felismina; DOS SANTOS OLIVEIRA, DANIELAMalaria is a major public health challenge worldwide and requires accurate and efficient diagnostic methods. Traditional diagnostic approaches based on antigen–antibody interactions are associated with ethical and economic concerns. Molecularly imprinted polymers (MIPs) offer a promising alternative by providing a complementary polymer structure capable of selectively binding target molecules. In this study, we developed a liquid, redox-probe-free, MIP-based electrochemical biosensor to detect the Plasmodium falciparum malaria marker histidine-rich protein (HRP2) at the point-of-care (PoC). The imprinting phase consists of the electropolymerization of the monomer methylene blue (MB) in the presence of the target protein HRP2 at the working electrode (WE) of the modified carbon screen printed electrode (C-SPE). Subsequent removal of the protein with proteinase K and oxalic acid yielded the MIP material. The sensor assembly was monitored by cyclic voltammetry (CV), Raman spectroscopy and scanning electron microscopy (SEM). The analytical performance of the biosensor was evaluated by square-wave voltammetry (SWV) using calibration curves in buffer and serum with a detection limit of 0.43 ± 0.026 pg mL–1. Selectivity studies showed minimal interference, indicating a highly selective assay. Overall, our approach to detect the HRP2 infection marker offers simplicity, cost-effectiveness and reliability. In particular, the absence of a redox solution simplifies detection, as the polymer itself is electroactive and exhibits oxidation and reduction peaks.
- Molecularly imprinting for ca 15-3 protein detection: a promising biosensor for advanced point-of-care applicationsPublication . Oliveira, Daniela; Barcelay, Yonny Romaguera; Moreira, Felismina(Introduction) Cancer is a public health problem worldwide. Early detection is crucial to improve survival rates [1]. Non-invasive, fast rapid, and low-cost diagnostic methods are urgently needed. Biosensors are a promising alternative to traditional methods such as ELISA, enabling point-ofcare (PoC) analyses. These require biorecognition elements with high selectivity and stability to meet current requirements in PoC diagnostics [2]. This work aims to create an electrochemical biosensor that can detect CA 15-3 with high sensitivity and selectivity. The biosensor consists of molecularly imprinted polymer (MIP) as the biorecognition element, and it is assembled via electrochemical polymerization of a mixture of 3-acrylamidopropyl trimethylammonium chloride (AMPTMA) in the presence of CA 15-3. Electrochemical techniques such as cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) were employed to evaluate the biosensor's electrochemical performance during its optimization and construction. CA 15-3 was successfully detected in a wide concentration range from 0.001 to 100 U mL-1 in just 20 minutes, with an R2 of 0.994. The MIP sensor showed minimal interference with other cancer proteins. This device offers rapid, sensitive, and cost-effective detection of CA 15-3, making it suitable for clinical PoC application.