Andrea Rossi, Lili Wang, Vytas Reipa, Thomas E. Murphy
Nanoporous silicon was discovered in the 1950 s and has unique properties due to quantum confinement effects. It is produced by electrochemical etching in HF containing electrolytes that allows to tune the pore diameter from a few nanometers up to several hundred nanometers by adjusting the etching parameters. Ensuing highly reactive hydrogen terminated internal pore surface allows to immobilize large quantities of biomolecules in a relatively small volume through bioconjugation. Consequently, PS can serve as a versatile platform for a biosensor with optical or electrical detection. Here we present our results in developing a prototype of the fluorescence based virus sensor based on nanoporous silicon. Bacteriophage virus MS2 was chosen as a model analyte that is used for simulating biological warfare agents. It is a 27 nm RNA virus that infects male Escherichia coli male. We have successfully conjugated a rabbit anti-MS2 antibody inside the PS film using two covalent conjugation protocols. Antibody binding strength and porous layer penetration measurements showed that maintaining Si surface hydrophilicity is critical in achieving high protein concentrations inside the nano-pore. Fluorescence measurements of the Alexa-532 labeled MS2 virus, captured by a 100 nm film exhibited similar sensitivity and dynamic range than the Luminex liquid array-based assay while clearly outperforming the protein micro-array device.
fluorescence, MS2, nanoporous, protein immobilization, silicon, virus detection
, Wang, L.
, Reipa, V.
and Murphy, T.
Porous Silicon Biosensor for MS2 Virus, Analytical Chemistry, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=830532
(Accessed June 8, 2023)