TY  - JOUR
A1  - Balderas-Valadez, Ruth Fabiola
A1  - Estevez-Espinoza, J. O.
A1  - Salazar-Kuri, U.
A1  - Pacholski, Claudia
A1  - Mochan, Wolf Luis
A1  - Agarwal, Vivechana
T1  - Fabrication of ordered tubular porous silicon structures by colloidal lithography and metal assisted chemical etching
BT  - SERS performance of 2D porous silicon structures
JF  - Applied surface science : a journal devoted to applied physics and chemistry of surfaces and interfaces
N2  - 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.
KW  - SERS
KW  - Porous silicon
KW  - MACE
KW  - Colloidal lithography
KW  - PolyNIPAM
KW  - 6-Mercaptopurine
Y1  - 2018
U6  - https://doi.org/10.1016/j.apsusc.2018.08.120
SN  - 0169-4332
SN  - 1873-5584
VL  - 462
SP  - 783
EP  - 790
PB  - Elsevier
CY  - Amsterdam
ER  -