Porous silicon as a platform for immobilization of biotin anti-human IL-6; rat IgG2a antibody onto p-type porous silicon via physical absorption method

Immobilization of biotin anti-human IL-6; rat IgG2a antibody onto porous silicon (PS) formed by an electrochemical anodization of p-type silicon surfaces has been reported. Chemical surface characterization by means of Fourier transformation infrared (FTIR) absorption spectroscopy, contact angle measurements and X-ray photoelectron spectroscopy (XPS), confirmed the efficiency of PS as entrapping template for the specific immobilization of IgG2a antibody via physical absorption process. The antibody presence was detected monitoring both the C 1s and N 1s signals in XPS spectra and amide I absorption band in the FTIR spectra of immobilized PS layer. These findings were also supported by photoluminescence (PL) spectroscopy, which showed significant reduction in the PL peak intensity by the presence of the antibody. The PL quenching was utilized as an indicator for sensing the effect of pH of antibody solution on immobilization process.