Near ambient pressure X-ray photoelectron spectroscopy monitoring of the surface immobilization cascade on a porous silicon-gold nanoparticle FET biosensor
Entity
UAM. Departamento de Física AplicadaPublisher
ElsevierDate
2019-10-30Citation
10.1016/j.apsusc.2019.06.056
Applied Surface Science 492 (2019): 362-368
ISSN
0169-4332DOI
10.1016/j.apsusc.2019.06.056Funded by
We acknowledge MSC funding provided by the European Commission through FP7 grant THINFACE (ITN GA 607232) and from Ministerio de Economía y Competitividad, Spain, through grant SPECTRASENSE (RTC-2017-6311-1)Project
Gobierno de España. RTC-2017-6311-1; info:eu-repo/grantAgreement/EC/FP7/607232//EU/THINFACEEditor's Version
https://doi.org/10.1016/j.apsusc.2019.06.056Subjects
Porous silicon; Biosenssor; Near ambient pressure X-ray photoelectron spectroscopy; FET; Sandwich bioassay; Gold nanoparticles; FísicaEsta obra está bajo una licencia de Creative Commons Reconocimiento-NoComercial-SinObraDerivada 4.0 Internacional.
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
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Google Scholar:Rodriguez, Chloé
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Dietrich, Paul
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Torres Costa, Vicente
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Cebrián, Virginia
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Gómez Abad, Cristina
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Díaz, Ana
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Ahumada, Óscar
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Manso Silván, Miguel
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