by Chloé Rodriguez, Paul Dietrich, Vicente Torres-Costa, Virginia Cebrián, Cristina Gómez-Abad, Ana Díaz, Oscar Ahumada and Miguel Manso Silván
Abstract:
Porous silicon (PSi) offers extremely attractive optical, electronic and biofunctional properties for the development of biosensors. In the present work, we have studied the step by step sandwich biofunctionalization cascade of a PSi platform by near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and, in parallel, we have developed a three electrode PSi device sensitive to changes in surface conductance. Prior to the NAP-XPS characterization, the organosilanization with glycidyloxy-propyl-trimethoxy-silane, the bioconjugation, and the gold nanoparticle (AuNP) sensitization layer were monitored by spectroscopic ellipsometry. The NAP-XPS analysis revealed outstanding results: a) the NAP-XPS chamber allows detecting the pristine PSi with negligible adventitious carbon contamination, b) the single oxygen bonded carbon component of the Glycidyl group dominates the C1s core level after organosilanization, c) the good progress of the biofunctionalization/recognition is confirmed by the increase of the silica to silicon component ratio in the Si2p core level and, d) the N1s core level describes identical features from the presence of aminoacid sequences in the capture/detection steps. A FET sensing of a prostate specific antigen (PSA) marker was performed through conjugation with AuNPs. For a given concentration of PSA (and AuNPs) the conductance increased with the increase of the gate voltage. For a given gate voltage, the conductance was observed to increase for increasing concentration of PSA. This allowed proposing a calibration line for the biosensor, which is valid from a clinically relevant range of 0.1 ng/mL.
Reference:
Chloé Rodriguez, Paul Dietrich, Vicente Torres-Costa, Virginia Cebrián, Cristina Gómez-Abad, Ana Díaz, Oscar Ahumada and Miguel Manso Silván, “Near ambient pressure X-ray photoelectron spectroscopy monitoring of the surface immobilization cascade on a porous silicon-gold nanoparticle FET biosensor”, Applied Surface Science, vol. 492, pp. 362–368.
Bibtex Entry:
@article{rodriguez_near_2019, title = {Near ambient pressure {X}-ray photoelectron spectroscopy monitoring of the surface immobilization cascade on a porous silicon-gold nanoparticle {FET} biosensor}, volume = {492}, issn = {0169-4332}, url = {http://www.sciencedirect.com/science/article/pii/S0169433219317507}, doi = {10.1016/j.apsusc.2019.06.056}, abstract = {Porous silicon (PSi) offers extremely attractive optical, electronic and biofunctional properties for the development of biosensors. In the present work, we have studied the step by step sandwich biofunctionalization cascade of a PSi platform by near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and, in parallel, we have developed a three electrode PSi device sensitive to changes in surface conductance. Prior to the NAP-XPS characterization, the organosilanization with glycidyloxy-propyl-trimethoxy-silane, the bioconjugation, and the gold nanoparticle (AuNP) sensitization layer were monitored by spectroscopic ellipsometry. The NAP-XPS analysis revealed outstanding results: a) the NAP-XPS chamber allows detecting the pristine PSi with negligible adventitious carbon contamination, b) the single oxygen bonded carbon component of the Glycidyl group dominates the C1s core level after organosilanization, c) the good progress of the biofunctionalization/recognition is confirmed by the increase of the silica to silicon component ratio in the Si2p core level and, d) the N1s core level describes identical features from the presence of aminoacid sequences in the capture/detection steps. A FET sensing of a prostate specific antigen (PSA) marker was performed through conjugation with AuNPs. For a given concentration of PSA (and AuNPs) the conductance increased with the increase of the gate voltage. For a given gate voltage, the conductance was observed to increase for increasing concentration of PSA. This allowed proposing a calibration line for the biosensor, which is valid from a clinically relevant range of 0.1 ng/mL.}, language = {en}, urldate = {2020-02-13}, journal = {Applied Surface Science}, author = {Rodriguez, Chloé and Dietrich, Paul and Torres-Costa, Vicente and Cebrián, Virginia and Gómez-Abad, Cristina and Díaz, Ana and Ahumada, Oscar and Manso Silván, Miguel}, month = oct, year = {2019}, keywords = {Porous silicon, Biosensor, Gold nanoparticles, Sandwich bioassay, FET, Near ambient pressure X-ray photoelectron spectroscopy}, pages = {362--368}, file = {ScienceDirect Full Text PDF:E:\Usuarios\Administrator\Zotero\storage\4J6PTYRK\Rodriguez et al. - 2019 - Near ambient pressure X-ray photoelectron spectros.pdf:application/pdf;ScienceDirect Snapshot:E:\Usuarios\Administrator\Zotero\storage\T4QAB9CH\S0169433219317507.html:text/html}, }