Response to cardiac markers in human serum analyzed by guided-mode resonance biosensor.
Cardiac markers in human serum with concentrations less than 0.1 ng/mL were analyzed by use of a guided-mode resonance (GMR) biosensor. Cardiac troponin I (cTnI), creatine kinase MB (CK-MB), and myoglobin (MYO) were monitored in the serum of both patients and healthy controls. Dose-response curves ranging from 0.05 to 10 ng/mL for cTnI, from 0.1 to 10 ng/mL for CK-MB, and from 0.03 to 1.7 μg/mL for MYO were obtained. The limits of detection (LOD) for cTnI, CK-MB, and MYO were less than 0.05, 0.1, and 35 ng/mL, respectively. Analysis time was 30 min, which is short enough to meet clinical requirements. Antibody immobilization and the hydrophilic properties of the guided-mode resonance filter (GMRF) surface were investigated by X-ray photoelectron spectroscopy (XPS) and by monitoring the peak wavelength shift and water contact angle (CA). Both assays used to evaluate the surface density of the immobilized antibodies, a sandwich enzyme-linked immunosorbent assay (ELISA) and a sandwich immunogold assay, showed that the antibodies were successfully immobilized and sufficiently aligned to detect the low concentration of biomarkers. Our results show that the GMR biosensor will be very useful in developing low-cost portable biosensors that can screen for cardiac diseases.
Biosensor Research Team, Electronics and Telecommunications Research Institute, Daejeon 305-700, South Korea.
Wan-Joong
WJ
Kim
Bong Kyu
BK
Kim
Ansoon
A
Kim
Chul
C
Huh
Chil Seong
CS
Ah
Kyung-Hyun
KH
Kim
Jongcheol
J
Hong
Seon Hee
SH
Park
Sanghoon
S
Song
Junghan
J
Song
Gun Yong
GY
Sung
D055910:Antibodies, Immobilized / Q000737:chemistry / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D015374:Biosensing Techniques / Q000379:methods*; D052279:Creatine Kinase, MB Form / Q000097:blood*; D006046:Gold / Q000737:chemistry; D006801:Humans; D009211:Myoglobin / Q000097:blood*; D056951:Photoelectron Spectroscopy; D019210:Troponin I / Q000097:blood*
D055910:Antibodies, Immobilized; D015415:Biomarkers; D009211:Myoglobin; D019210:Troponin I; D006046:Gold; D052279:Creatine Kinase, MB Form