Fabrication of ordered tubular porous silicon structures by colloidal lithography and metal assisted chemical etching: SERS performance of 2D porous silicon structures
Por:
Balderas-Valadez, R. F., Estevez-Espinoza, J. O., Salazar-Kuri, U., Pacholski, C., Mochan, W. L., Agarwal, V.
Publicada:
31 dic 2018
Categoría:
Surfaces, coatings and films
Resumen:
Fabrication of well-ordered porous silicon tubular structures using
colloidal lithography and metal assisted chemical etching is reported. A
continuous hexagonal hole/particle gold pattern was designed over
monocrystalline silicon through deposition of polyNIPAM microspheres,
followed by the surface decoration with gold nanoparticles and thermal
treatment. An etching reaction with HF, ethanol and H2O2 dissolved the
silicon in contact with the metal nanoparticles (NP), creating a porous
tubular array in the ``off-metal area''. The morphological
characterization revealed the formation of a cylindrical hollow porous
tubular shape with external and internal diameter of approx. 900 nm and
400 nm respectively, though it can be tuned to other desired sizes by
choosing an appropriate dimension for the microspheres. The porous
morphology and optical properties were studied as a function of
resistivity of silicon substrates. Compared to two different gold
templates on cSi and nontubular porous pillar structures, porous silicon
tubular framework revealed a maximum surface enhanced Raman scattering
enhancement factor of 10(6) for the detection of 6-mercaptopurine
(6-MP). Due to the large surface area available for any surface
modification, open nanostructured platforms such as those studied here
have potential applications in the field of reflection/photoluminescene
and SERS based optical bio-/chemical sensors.
Filiaciones:
Balderas-Valadez, R. F.:
Univ Autonoma Estado Morelos, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca, Morelos, Mexico
Univ Potsdam, Inst Chem, Potsdam, Germany
Estevez-Espinoza, J. O.:
Univ Nacl Autonoma Mexico, Inst Fis, Dept Mat Condensada, Mexico City, DF, Mexico
Salazar-Kuri, U.:
Benemerita Univ Autonoma Puebla, Inst Fis, Puebla, Pue, Mexico
Pacholski, C.:
Univ Potsdam, Inst Chem, Potsdam, Germany
Mochan, W. L.:
Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Apartado Postal 48-3, Cuernavaca 62251, Morelos, Mexico
Agarwal, V.:
Univ Autonoma Estado Morelos, Ctr Invest Ingn & Ciencias Aplicadas, Cuernavaca, Morelos, Mexico
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