Characterization of hydrophobic, oxidized porous silicon layer formed by anodic etching of n+-type silicon surface in a HF:C2H5OH:HCl:H2O2:H2O electrolyte for bio-application
Abstract
Porous silicon (PS) has been prepared in the dark by anodic etching of n+-type (111) silicon substrate in a HF:HCl:C2H5OH:H2O2:H2O electrolyte. The processed PS layer is characterized by means of photoluminescence (PL) spectroscopy, scanning electron microscope (SEM), water contact angle (CA) measurements, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and micro-Raman scattering. The CA of fresh PS layer is found to be ~142°. On aging at ambient conditions, the CA decreases gently to reach ~133° after 3 month, and then it is stabilized for a prolonged time of aging. The visible PL emission from the PS layer also exhibits a good stability against aging time. The FTIR and XPS measurements and analysis show that the stable aged PS layer has rather SiO2-rich surface. The micro/nanostructure nature of the PS layer is revealed from SEM and micro-Raman results and correlated to CA results. Stable hydrophobic surface of oxidized PS layer is attractive for bio-applications. The efficiency of the produced PS layers as an entrapping template for specific immobilization of IgG2a antibody via physical absorption process is demonstrated.
- Publication:
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Applied Physics A: Materials Science & Processing
- Pub Date:
- September 2014
- DOI:
- 10.1007/s00339-014-8230-9
- Bibcode:
- 2014ApPhA.116.1337N
- Keywords:
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- Contact Angle;
- Porous Silicon;
- Electrochemical Etching;
- Porous Silicon Layer;
- IgG2a Antibody