Toward sensitive immuno-based detection of tau protein by surface plasmon resonance coupled to carbon nanostructures as signal amplifiers.
Interest on Tau protein is fast increasing in Alzheimer's disease (AD) diagnosis. There is the urgent need of highly sensitive and specific diagnostic platforms for its quantification, also in combination with the other AD hallmarks. Up to now, SPR has been poorly exploited for tau detection by immunosensing, due to sensitivity limits at nanomolar level, whereas the clinical requirement is in the picomolar range. Molecular architectures built in a layer-by-layer fashion, biomolecules and nanostructures (metallic or not) may amplify the SPR signal and improve the limit of detection to the desired sensitivity. Mostly gold nanostructures are widely employed to this aim, but great interest is also emerging in Multi Walled Carbon Nanotubes (MWCNTs). Here MWCNTs are modified and then decorated with the secondary antibody for tau protein. Eventually we took advantage from MWCNTs-antibody conjugate to obtain a sandwich-based bioassay with the capability to increase the SPR signal of about 102folds compared to direct detection and conventional unconjugated sandwich. With respect to these results, we hope to give a strong impulse for further investigation on studying possible roles of carbon nanotubes in optical-based biosensing.
Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019 Florence, Italy; Dèpartement de pharmacochimie moléculaire, UMR 5063, CNRS, ICMG FR 2607, Université de Grenoble Alpes, Grenoble Campus, Cedex 9, 38400 St. Martin d'Heres, France.
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Lisi
Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019 Florence, Italy.
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Scarano
Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019 Florence, Italy.
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Fedeli
Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019 Florence, Italy.
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Pascale
Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019 Florence, Italy.
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Cicchi
Dèpartement de pharmacochimie moléculaire, UMR 5063, CNRS, ICMG FR 2607, Université de Grenoble Alpes, Grenoble Campus, Cedex 9, 38400 St. Martin d'Heres, France.
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Ravelet
Dèpartement de pharmacochimie moléculaire, UMR 5063, CNRS, ICMG FR 2607, Université de Grenoble Alpes, Grenoble Campus, Cedex 9, 38400 St. Martin d'Heres, France.
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Peyrin
Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino, 50019 Florence, Italy. Electronic address: maria.minunni@unifi.it.
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Minunni
D000544:Alzheimer Disease / Q000175:diagnosis* / Q000378:metabolism; D000669:Amplifiers, Electronic; D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D020349:Surface Plasmon Resonance; D016875:tau Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*
D000906:Antibodies; D037742:Nanotubes, Carbon; D016875:tau Proteins; D006046:Gold
Alzheimer's disease; Carbon nanotubes; Signal amplification; Surface plasmon resonance; Tau protein