Fast label-free detection of C-reactive protein using broad-band Mach-Zehnder interferometers integrated on silicon chips.
An immunosensor for fast and accurate determination of C-reactive protein (CRP) in human serum samples based on an array of all-silicon broad-band Mach-Zehnder interferometers (BB-MZIs) is demonstrated. The detection was based on monitoring the spectral shifts during the binding of CRP on the antibody molecules that have been immobilized on the sensing arms of the BB-MZIs. By employing the reaction rate as the analytical signal the assay time was compressed to few minutes. The detection limit was 2.1ng/mL, the quantification limit was 4.2ng/mL and the linear dynamic range extended up to 100ng/mL. The measurements performed in human serum samples with the developed immunosensor were characterized by high repeatability and accuracy as it was demonstrated by dilution linearity and recovery experiments. In addition, the concentration values determined were in excellent agreement with those determined for the same samples by a standard clinical laboratory method. The compact size of the chip makes the proposed immunosensor attractive for incorporation into miniaturized devices for the determination of clinical analytes at the point-of-need.
Immunoassay/Immunosensors Lab, Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR "Demokritos", Aghia Paraskevi, Greece; Laboratory of Analytical Chemistry, University of Grete, 71003 Iraklion, Greece.
Aimilia
A
Psarouli
Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", Aghia Paraskevi, Greece.
Athanasios
A
Botsialas
Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", Aghia Paraskevi, Greece.
Alexandros
A
Salapatas
Diagnostic Laboratories, "Henri Dunant" Hospital, 115 26 Athens, Greece.
Gerasimos
G
Stefanitsis
Diagnostic Laboratories, "Henri Dunant" Hospital, 115 26 Athens, Greece.
Dimitra
D
Nikita
Jobst Technologies GmbH, Freiburg, Germany.
Gerhard
G
Jobst
Laboratory of Analytical Chemistry, University of Grete, 71003 Iraklion, Greece.
Nikolaos
N
Chaniotakis
ThetaMetrisis S.A., Polydefkous 14, GR-12243 Athens, Greece; Electronics Eng. Dept., TEI of Piraeus, Athens, Greece.
Dimitrios
D
Goustouridis
Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", Aghia Paraskevi, Greece.
Eleni
E
Makarona
Immunoassay/Immunosensors Lab, Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR "Demokritos", Aghia Paraskevi, Greece. Electronic address: ypetrou@rrp.demokritos.gr.
Panagiota S
PS
Petrou
Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", Aghia Paraskevi, Greece.
Ioannis
I
Raptis
Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", Aghia Paraskevi, Greece.
Konstantinos
K
Misiakos
Immunoassay/Immunosensors Lab, Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR "Demokritos", Aghia Paraskevi, Greece.
Sotirios E
SE
Kakabakos
D015374:Biosensing Techniques / Q000379:methods*; D002097:C-Reactive Protein / Q000032:analysis*; D004867:Equipment Design; D006801:Humans; D007368:Interferometry / Q000295:instrumentation* / Q000379:methods*; D057230:Limit of Detection; D012825:Silicon / Q000737:chemistry*
D002097:C-Reactive Protein; D012825:Silicon
Broad-band Mach-Zehnder interferometer; C-reactive protein; Label-free immunosensor; Monolithic integration