Abstracts Book - IMRC 2018

• SB5-O008
PMMA-BASED MICROFLUIDIC SYSTEM FOR POINT-OF-CARE
APPLICATIONS
José Herrera Celis 1,2 , Euth Ortiz Ortega 1 , Luis Gerardo Arriaga 1 , Beatriz Liliana España Sánchez 3
1 Centro de Investigación y Desarrollo Tecnológico en Electroquímica, Generación de Energía
por Vía Electroquímica, Mexico. 2 Consejo Nacional de Ciencia y Tecnologia - CONACYT,
Cátedras CONACYT, Mexico. 3 Centro de Investigación y Desarrollo Tecnológico en
Electroquímica, Procesos Industriales y Recubrimientos, Mexico.
A versatile microfluidic system fabricated on poly(methyl methacrylate) (PMMA)
was implemented in order to perform the functionalization and testing
processes of a biosensor using a top interchangeable layer. The system is
conformed by two stacked PMMA layers. On the surface of the bottom layer, a
Ti/Au (20 nm/180 nm) interdigitated microelectrode array as biosenser was
formed by consecutive processes of photolithography, metal evaporation and
lift-off. Two different top layers were fabricated by CNC micromilling of PMMA
to be coupled to the bottom layer. One layer has the microchannel and
microcontainer to carry out the functionalization process of the biosensor,
whereas the other one has only a microcontainer to confine the sample of the
fluid under study. The bottom and top layers are aligned and hold together by
screws in combination with alignment pins. The PMMA surface between
interdigitated microelectrodes was trated with ethylenediamine to bind the
Escherichia coli (E. coli) bacteria throught amine groups. The functionalization
process was carried out controling the flow of the fluids by the microchannel. E.
coli samples with different concentrations were used to test the system. The
functionalization process was analyzed by Fourier transform infrarred (FTIR)
spectroscopy, and the behaviour of the biosensor was registered by electrical
impedance spectroscopy (EIS). The results showed that this microfluidic system
is low cost, easy fabrication, useful as point-of-care diagnostic tool, and reduces
the consumption of functionalization reagents.
Acknowledgment: The authors are thankful to the Laboratorio Nacional de
Micro y Nanofluídica (LabMyN) financed by the Consejo Nacional de Ciencia y
Tecnología (CONACYT) under the project LN-293442.
Keywords: PMMA, Microfluidic, Biosensor
Presenting authors email: jlherrera@cideteq.mx