title: Reproducible and label-free biosensor for the selective extraction and rapid detection of proteins in biological fluids.
abstract: Erythropoietin (EPO), a glycoprotein hormone of ∼ 34 kDa, is an important hematopoietic growth factor, mainly produced in the kidney and controls the number of red blood cells circulating in the blood stream. Sensitive and rapid recombinant human EPO (rHuEPO) detection tools that improve on the current laborious EPO detection techniques are in high demand for both clinical and sports industry. A sensitive aptamer-functionalized biosensor (aptasensor) has been developed by controlled growth of gold nanostructures (AuNS) over a gold substrate (pAu/AuNS). The aptasensor selectively binds to rHuEPO and, therefore, was used to extract and detect the drug from horse plasma by surface enhanced Raman spectroscopy (SERS). Due to the nanogap separation between the nanostructures, the high population and distribution of hot spots on the pAu/AuNS substrate surface, strong signal enhancement was acquired. By using wide area illumination (WAI) setting for the Raman detection, a low RSD of 4.92% over 150 SERS measurements was achieved. The significant reproducibility of the new biosensor addresses the serious problem of SERS signal inconsistency that hampers the use of the technique in the field. The WAI setting is compatible with handheld Raman devices. Therefore, the new aptasensor can be used for the selective extraction of rHuEPO from biological fluids and subsequently screened with handheld Raman spectrometer for SERS based in-field protein detection.
authors.affiliation: Nanotechnology and Molecular Sciences Discipline, Faculty of Science and Engineering, Queensland University of Technology, 2 George St., Brisbane, QLD, 4001, Australia. sivanesan.arumugam@qut.edu.au.
authors.forename: Arumugam
authors.initials: A
authors.lastname: Sivanesan
authors.affiliation: Nanotechnology and Molecular Sciences Discipline, Faculty of Science and Engineering, Queensland University of Technology, 2 George St., Brisbane, QLD, 4001, Australia. e.kiriakous@qut.edu.au.
authors.forename: Emad L
authors.initials: EL
authors.lastname: Izake
authors.affiliation: Nanotechnology and Molecular Sciences Discipline, Faculty of Science and Engineering, Queensland University of Technology, 2 George St., Brisbane, QLD, 4001, Australia. r.agoston@qut.edu.au.
authors.forename: Roland
authors.initials: R
authors.lastname: Agoston
authors.affiliation: Nanotechnology and Molecular Sciences Discipline, Faculty of Science and Engineering, Queensland University of Technology, 2 George St., Brisbane, QLD, 4001, Australia. g.ayoko@qut.edu.au.
authors.forename: Godwin A
authors.initials: GA
authors.lastname: Ayoko
authors.affiliation: Discipline of Biosciences, Faculty of Science and Engineering, Queensland University of Technology, 2 George St., Brisbane, QLD, 4001, Australia. martin.sillence@qut.edu.au.
authors.forename: Martin
authors.initials: M
authors.lastname: Sillence
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D004921:Erythropoietin / Q000097:blood* / Q000302:isolation & purification; D006046:Gold / Q000737:chemistry*; D006736:Horses / Q000097:blood*; D006801:Humans; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry*; D011994:Recombinant Proteins / Q000097:blood / Q000302:isolation & purification; D015203:Reproducibility of Results; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D052157:Aptamers, Nucleotide; C554270:EPO protein, human; D011994:Recombinant Proteins; D004921:Erythropoietin; D006046:Gold