title: Disposable integrated bismuth citrate-modified screen-printed immunosensor for ultrasensitive quantum dot-based electrochemical assay of C-reactive protein in human serum.
abstract: A novel immunosensor based on graphite screen-printed electrodes (SPEs) modified with bismuth citrate was developed for the voltammetric determination of C-reactive protein (CRP) in human serum using quantum dots (QDs) labels. The sandwich-type immunoassay involved physisorption of CRP capture antibody on the surface of the sensor, sequential immunoreactions with CRP and biotinylated CRP reporter antibody and finally reaction with streptavidin-conjugated PbS QDs. The quantification of the target protein was performed with acidic dissolution of the PbS QDs and anodic stripping voltammetric detection of the Pb(II) released. Detection was performed at bismuth nanodomains formed on the sensor surface during the electrolytic preconcentration step, as bismuth citrate was reduced to metallic bismuth simultaneously with the deposition of Pb on the surface of the immunosensor. Under optimal conditions, the response was linear over the range 0.2-100 ng mL(-1) CRP and the limit of detection was 0.05 ng mL(-1) CRP. Since the modified SPE serves as both the biorecognition element and the QDs reader, the analytical procedure is simplified, the drawbacks of existing electroplated immunosensors are minimized while the proposed disposable sensing platform provides convenient, low-cost and ultrasensitive detection of proteins and wider scope for mass-production.
authors: Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece. Electronic address: xkokkinos@gmail.com.
authors: Christos
authors: C
authors: Kokkinos
authors: Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
authors: Mamas
authors: M
authors: Prodromidis
authors: Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, 157 71 Athens, Greece.
authors: Anastasios
authors: A
authors: Economou
authors: Immunoassay/Immunosensors Lab, Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR "Demokritos", Aghia Paraskevi, 153 10 Athens, Greece.
authors: Panagiota
authors: P
authors: Petrou
authors: Immunoassay/Immunosensors Lab, Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR "Demokritos", Aghia Paraskevi, 153 10 Athens, Greece.
authors: Sotirios
authors: S
authors: Kakabakos
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation; D002097:C-Reactive Protein / Q000032:analysis*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D057230:Limit of Detection; D009942:Organometallic Compounds / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*
chemical_list: D055910:Antibodies, Immobilized; D009942:Organometallic Compounds; D002097:C-Reactive Protein; C002791:bismuth tripotassium dicitrate
keywords: C-reactive protein; Immunosensor; Quantum dots; Screen-printed electrode; Stripping voltammetry