Electrochemical immunosensor for simultaneous determination of interleukin-1 beta and tumor necrosis factor alpha in serum and saliva using dual screen printed electrodes modified with functionalized double-walled carbon nanotubes.
Dual screen-printed carbon electrodes modified with 4-carboxyphenyl-functionalized double-walled carbon nanotubes (HOOC-Phe-DWCNTs/SPCEs) have been used as scaffolds for the preparation of electrochemical immunosensors for the simultaneous determination of the cytokines Interleukin-1β (IL-1β) and factor necrosis tumor α (TNF-α). IL-1β. Capture antibodies were immobilized onto HOOC-Phe-DWCNTs/SPCEs in an oriented form making using the commercial polymeric coating Mix&Go™. Sandwich type immunoassays with amperometric signal amplification through the use of poly-HRP-streptavidin conjugates and H2O2as HRP substrate and hydroquinone as redox mediator were implemented. Upon optimization of the experimental variables affecting the immunosensor performance, the dual immunosensor allows ranges of linearity extending between 0.5 and 100 pg/mL and from 1 to 200 pg/mL for IL-1β and TNF-α, respectively, these ranges being adequate for the determination of the cytokines in clinical samples. The achieved limits of detection were 0.38 pg/mL (IL-1β) and 0.85 pg/mL (TNF-α). In addition, the dual immunosensor exhibits excellent reproducibility of the measurements, storage stability of the anti-IL-Phe-DWCNTs/SPCE and anti-TNF-Phe-DWCNTs/SPCE conjugates, and selectivity as well as negligible cross-talking. The dual immunosensor was applied to the simultaneous determination of IL-1β and TNF-α in human serum spiked at clinically relevant concentration levels and in real saliva samples.
Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
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Sánchez-Tirado
Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
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Salvo
Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
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González-Cortés
Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain. Electronic address: yseo@quim.ucm.es.
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Yáñez-Sedeño
Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha, 45071, Toledo, Spain.
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Langa
Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
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Pingarrón
D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D004566:Electrodes; D006801:Humans; D006861:Hydrogen Peroxide; D007118:Immunoassay; D053583:Interleukin-1beta / Q000032:analysis* / Q000097:blood; D037742:Nanotubes, Carbon; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis* / Q000097:blood
C508585:IL1B protein, human; D053583:Interleukin-1beta; D037742:Nanotubes, Carbon; D014409:Tumor Necrosis Factor-alpha; D006861:Hydrogen Peroxide
Double-walled carbon nanotubes; Electrochemical immunosensor; Interleukin-1 beta; Multiplex; Saliva; Tumor necrosis factor-alpha