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Surface plasmon resonance biosensor for parallelized detection of protein biomarkers in diluted blood plasma

2010; Elsevier BV; Volume: 26; Issue: 4 Linguagem: Inglês

10.1016/j.bios.2010.08.063

1873-4235

Marek Piliarik, Markéta Bocková, Jiřı́ Homola,

Advanced Biosensing Techniques and Applications

Surface plasmon resonance (SPR) biosensor for high-throughput screening of protein biomarkers in diluted blood plasma is reported. The biosensor combines a high-resolution SPR imaging sensor and a high-density protein array with low-fouling background. The SPR imaging sensor utilizes polarization contrast and advanced referencing and provides a total of 120 sensing areas (each 200 μm × 150 μm). Antibodies are immobilized on the sensing areas via hybridization of antibody–oligonucleotide conjugates to thiolated complementary oligonucleotides microspotted on the sensor surface (DNA-directed immobilization). A low-fouling background is achieved by covalent immobilization of bovine serum albumin to carboxyl-terminated thiols filling the areas among the thiolated oligonucleotides and outside the sensing areas. The biosensor was evaluated for detection of protein biomarkers relevant to cancer diagnostics—human chorionic gonadotropin (hCG) and activated leukocyte cell adhesion molecule (ALCAM) both in buffer and in 10% blood plasma. Limits of detection as low as 45 ng/mL (ALCAM) and 100 ng/mL (hCG) were achieved in blood plasma samples.