Detection of ferritin by surface plasmon resonance under mass transport-limited

surface plasmon resonance (SPR) biosensor has been used to determine the concentration of ferritin under mass transport-limited condition. The interaction of antibody with antigen was under mass transport-limited because of the high molecular weight of ferritin and controlling high antibody immobilization amount and low flow rate. Binding rate analysis method was then used to determine ferretin concentration. The linear range of the assay is over 20 similar to 800 mu g/L, which is much broader than the sandwich amplifying method. The limit of detection was 20 mu g/L. The biosensor can be regenerated by pH 2.0 glycine-HCl buffer and the same antibody immobilized surface can be used more than 50 cycles of ferritin binding and regeneration.