TY - JOUR
T1 - Red blood cells do not attenuate the SPCE fluorescence in surface assays
AU - Matveeva, Evgenia G.
AU - Gryczynski, Ignacy
AU - Barnett, Anne
AU - Calander, Nils
AU - Gryczynski, Zygmunt
N1 - Funding Information:
Acknowledgments This research was supported by NIH: NCI CA-114460, the National Institute of Biomedical Imaging and Bioengineering EB-1690, AR-048622, the Biomolecular Interaction Technology Center (University of New Hampshire), and Philip Morris USA, Inc. We acknowledge the support from Texas Emerging Technologies Fund. We thank Prof. Agustina Gómez-Hens (University of Córdoba, Spain) for valuable discussion of the manuscript.
PY - 2007/7
Y1 - 2007/7
N2 - We describe the positive effect of surface plasmon-coupled fluorescence emission (SPCE) on the detection of a signal from a surface immunoassay in highly absorbing or/and scattering samples. A model immunoassay using fluorescently labeled anti-rabbit antibodies that bind to rabbit immunoglobulin on a silver surface was performed, and the signal was detected in the presence of various highly absorbing and/or scattering solutions or suspensions, such as hemoglobin solution, plastic beads, and red blood cells. The results showed that a highly absorbing solution consisting of small molecules (dye, hemoglobin) attenuates the SPCE signal approximately 2-3-fold. In contrast, suspensions with the same absorption containing large particles (large beads, red blood cell suspension) attenuate the SPCE signal only slightly, approximately 5-10%. Also, a suspension of large undyed, highly scattering beads does not reduce the SPCE signal. The effects on the immunoassay signal of the sample background absorption and scattering, the size of the background particles, and the geometry of the experimental set-up are discussed. We believe that SPCE is a promising technique in the development of biosensors utilized for surface-based assays, as well as any assays performed directly in highly absorbing and/or scattering solutions without washing or separation procedures. [Figure not available: see fulltext.].
AB - We describe the positive effect of surface plasmon-coupled fluorescence emission (SPCE) on the detection of a signal from a surface immunoassay in highly absorbing or/and scattering samples. A model immunoassay using fluorescently labeled anti-rabbit antibodies that bind to rabbit immunoglobulin on a silver surface was performed, and the signal was detected in the presence of various highly absorbing and/or scattering solutions or suspensions, such as hemoglobin solution, plastic beads, and red blood cells. The results showed that a highly absorbing solution consisting of small molecules (dye, hemoglobin) attenuates the SPCE signal approximately 2-3-fold. In contrast, suspensions with the same absorption containing large particles (large beads, red blood cell suspension) attenuate the SPCE signal only slightly, approximately 5-10%. Also, a suspension of large undyed, highly scattering beads does not reduce the SPCE signal. The effects on the immunoassay signal of the sample background absorption and scattering, the size of the background particles, and the geometry of the experimental set-up are discussed. We believe that SPCE is a promising technique in the development of biosensors utilized for surface-based assays, as well as any assays performed directly in highly absorbing and/or scattering solutions without washing or separation procedures. [Figure not available: see fulltext.].
KW - Background suppression
KW - Fluorescence immunoassays
KW - Hemoglobin
KW - Red blood cells
KW - Surface plasmon-coupled emission
UR - http://www.scopus.com/inward/record.url?scp=34547299843&partnerID=8YFLogxK
U2 - 10.1007/s00216-007-1322-z
DO - 10.1007/s00216-007-1322-z
M3 - Article
C2 - 17534609
AN - SCOPUS:34547299843
SN - 1618-2642
VL - 388
SP - 1127
EP - 1135
JO - Analytical and Bioanalytical Chemistry
JF - Analytical and Bioanalytical Chemistry
IS - 5-6
ER -