On the importance of controlling film architecture in detecting prostate specific antigen

Autor(es)

Graca, Juliana Santos ^[1] ; Miyazaki, Celina Massumi ^[1] ; Shimizu, Flavio Makoto ^[2] ; Volpati, Diogo ^[3] ; Mejia-Salazar, J. R. ^[2] ; Oliveira, Jr., Osvaldo N. ^[2] ; Ferreira, Marystela ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Ctr Sci & Technol Sustainabil, BR-18055720 Sorocaba, SP - Brazil

^[2] Univ Sao Paulo, Sao Carlos Inst Phys, POB 369, BR-13560970 Sao Carlos, SP - Brazil

^[3] Mid Sweden Univ, Dept Nat Sci, SE-85170 Sundsvall - Sweden

• Tipo de documento: Artigo Científico
• Fonte: Applied Surface Science; v. 434, p. 1175-1182, MAR 15 2018.
• Citações Web of Science: 3

Resumo

Immunosensors made with nanostructured films are promising for detecting cancer biomarkers, even at early stages of the disease, but this requires control of film architecture to preserve the biological activity of immobilized antibodies. In this study, we used electrochemical impedance spectroscopy (EIS) to detect Prostate Specific Antigen (PSA) with immunosensors produced with layer-by-layer (LbL) films containing anti-PSA antibodies in two distinct film architectures. The antibodies were either adsorbed from solutions in which they were free, or from solutions where they were incorporated into liposomes of dipalmitoyl phosphatidyl glycerol (DPPG). Incorporation into DPPG liposomes was confirmed with surface plasmon resonance experiments, while the importance of electrostatic interactions on the electrical response was highlighted using the Finite Difference Time-Domain Method (FDTD). The sensitivity of both architectures was sufficient to detect the threshold value to diagnose prostate cancer (ca. 4 ng mL(-1)). In contrast to expectation, the sensor with the antibodies incorporated into DPPG liposomes had lower sensitivity, though the range of concentrations amenable to detection increased, according to the fitting of the EIS data using the Langmuir-Freundlich adsorption model. The performance of the two film architectures was compared qualitatively by plotting the data with a multidimensional projection technique, which constitutes a generic approach for optimizing immunosensors and other types of sensors. (C) 2017 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 14/15093-7 - Estudos de sistemas nanoestruturados por ressonância plasmônica de superfície (SPR): aplicações em biossensoriamento
• Beneficiário: Celina Massumi Miyazaki
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/14262-7 - Filmes nanoestruturados de materiais de interesse biológico
• Beneficiário: Osvaldo Novais de Oliveira Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 16/12311-9 - Efeito transversal magneto-óptico Kerr para o desenho e desenvolvimento de biosessores
• Beneficiário: Jorge Ricardo Mejía Salazar
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 12/15543-7 - Biossensores para detectar Escherichia coli usando o conceito de línguas eletrônicas
• Beneficiário: FLAVIO MAKOTO SHIMIZU
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/17519-1 - Imobilização de nanopartículas metálicas em filmes ultrafinos visando ao biossensoriamento
• Beneficiário: Marystela Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/23288-0 - Filmes nanoestruturados para detecção do Antígeno Prostático Específico (PSA - Prostate Specific Antigen)
• Beneficiário: Juliana Santos Graça
• Modalidade de apoio: Bolsas no Brasil - Mestrado