Immunoassay for P38 MAPK using surface enhanced resonance Raman spectroscopy (SERRS).
A micro-bead sandwich assay for P38 mitogen-activated protein kinase using surface enhanced resonance Raman spectroscopy (SERRS) detection is reported. Monoclonal capture antibodies were immobilised on a solid phase of magnetic micro-beads with secondary detection using a rhodamine-labelled antibody. Quantitative SERRS detection of the secondary antibody was possible with a limit of detection of 9.5 x 10(-12) mol dm(-3). The sandwich assay was quantitative and sensitive to 6 ng ml(-1). The mechanism of the SERRS detection in the immunoassay was investigated. The addition of SERRS aggregating agents causes the dissociation of the immuno-complex from the magnetic beads. Scanning electron microscopy images indicate that the colloidal suspension rather than adsorbed silver nanoparticles on the beads provide the SERRS signals, that the aggregate size is partially controlled and that there is some inhomogeneity in the distribution of organic matter on the nanoscale.
Douglas
Phil
P
Centre of Molecular Nanometrology, Department of Pure & Applied Chemistry, University of Strathclyde, 298 Cathedral Street, Glasgow, UK.
Stokes
Robert J
RJ
Graham
Duncan
D
Smith
W Ewen
WE
D003102:Colloids; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008280:Magnetics; D053768:Metal Nanoparticles; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011994:Recombinant Proteins / Q000032:analysis; D012235:Rhodamines; D012680:Sensitivity and Specificity; D012834:Silver; D013059:Spectrum Analysis, Raman; D048051:p38 Mitogen-Activated Protein Kinases / Q000032:analysis*
D003102:Colloids; D011994:Recombinant Proteins; D012235:Rhodamines; D012834:Silver; D048051:p38 Mitogen-Activated Protein Kinases