Surface plasmon resonance-based immunoassay for procalcitonin.
A surface plasmon resonance (SPR) biosensor has been developed for rapid immunoassay of procalcitonin (PCT) with high detection sensitivity and reproducibility. The 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC)-activated protein A (PrA), diluted in 1% (v/v) 3-aminopropyltriethoxysilane (APTES) was dispensed on a KOH-treated Au-coated SPR chip, resulting in the covalent binding of PrA in 30 min. This "single-step" PrA immobilization strategy led to the oriented binding of the anti-PCT antibody (Ab) on a PrA-functionalized gold (Au) chip. The leach-proof immobilization procedure is five-fold faster than conventional counterparts, enabling high detection specificity and reproducibility. The IA detects 4-324 ng mL(-1) of PCT with a limit of detection (LOD) and a limit of quantification (LOQ) of 4.2 ng mL(-1) and 9.2 ng mL(-1), respectively. It was capable of detecting PCT in real sample matrices and patient samples with high precision. The Ab-bound SPR chips were stable for more than five weeks.
Institute of Clinical Chemistry and Pathobiochemistry, Klinikum rechts der Isar der Technischen Universität München, Ismaninger Str. 22, D-81675, Munich, Germany. Electronic address: sandeep.vashist@yahoo.com.
Sandeep Kumar
SK
Vashist
Sektion Experimentelle Anaesthesiologie, University Hospital Ulm, Albert Einstein Allee 23, 89081 Ulm, Germany.
E Marion
EM
Schneider
Sektion Operative Intensive Care Medicine, Department Anesthesiology, University Hospital Ulm, Albert Einstein Allee 23, 89081, Ulm, Germany.
Eberhard
E
Barth
Innovative Chromatography Group, Irish Separation Science Cluster (ISSC), Department of Chemistry and Analytical, Biological Chemistry Research Facility (ABCRF), University College Cork, Cork, Ireland.
John H T
JH
Luong
D002116:Calcitonin / Q000032:analysis*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D020349:Surface Plasmon Resonance / Q000379:methods*
D002116:Calcitonin
APTES; Immunoassay; Procalcitonin; Protein A; Surface plasmon resonance