Conjugated Polymers Blended with Lipids and Galactosidase as Langmuir-Blodgett Films To Control the Biosensing Properties of Nanostructured Surfaces

Author(s)

Araujo, Felipe Tejada ^[1] ; Peres, Laura Oliveira ^[1] ; Caseli, Luciano ^[1]

Affiliation

^[1] Univ Fed Sao Paulo, BR-09913030 Diadema, SP - Brazil

• Document type: Journal article
• Source: Langmuir; v. 35, n. 22, p. 7294-7303, JUN 4 2019.
• Web of Science Citations: 3

Abstract

The structure of enzymes must be conserved when incorporated in nanoelectronic devices because their activity determines the function of the device as sensors. Among the systems that can retain their conformational structures, Langmuir-Blodgett (LB) films can be useful to exploit the construction of bioelectronic devices organized at the molecular level because biological and polymeric materials can be coupled as ultrathin films for biosensors and actuators. In this paper, we immobilized a beta-galactosidase enzyme in the LB films of stearic acid and the conjugated polymer poly{[}(9,9-dioctylfluorene)-co-thiophene]. After the characterization of the floating films using tensiometry, vibrational spectroscopy, and Brewster angle microscopy, they were transferred to solid supports as LB films, and the catalytic activity of the enzyme could be preserved as analyzed using UV-vis spectroscopy. We noted that the presence of a supramolecular structure formed in the LB films not only conserved the enzyme activity but also exhibited regular and distinctive output signals in all molecular architectures employed in this work. These results are related to the synergism between the compounds on the active layer associated with a surface morphology that facilitated the analyte diffusion because of an adequate molecular accommodation of all components. This work then demonstrates the viability of employing LB films composed of lipids, enzymes, and synthetic polymers as devices for biosensing applications. (AU)

• FAPESP's process: 19/03239-0 - Nanostructured interfaces for the investigation of bioactive substances in cell membrane models and for the construction of optoelectronic devices
• Grantee: Luciano Caseli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/50869-6 - INCT 2014: on Organic Electronics
• Grantee: Roberto Mendonça Faria
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/14262-7 - Nanostructured films from biologically-relevant materials
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/23446-0 - Smart surfaces: nanostructured and bioinspired systems for the investigation of molecular interactions in membrane models and for the production of devices for biosensors and environmental analysis
• Grantee: Luciano Caseli
• Support Opportunities: Regular Research Grants