Current Advances in Antibody Immobilization on Different Surfaces and Beads

Antibody immobilization is of considerable interest for miscellaneous fields of interest, e.g. detecting biomarkers in cancer diagnostics, e.g. prostate specific antigen (PSA) for prostate cancer and pathogens like Escherichia coli, a foodborne pathogen. For this purpose, specific antibody captures are required and all of them should guarantee highest reproducibility and capacity possible. Especially in clinical applications very complex and specific immunoassays are needed. However, the complexity of pinning antibodies necessitates particular methods concerning the immobilization technique itself- because of their structure and specificity- and of course the analyzing methods. Glass, polymers, gold and even fullerene beads have been used as carriers, treated with various spacers and activation steps within the last few years. Furthermore, considerable attention is drawn to the regeneration of matrices and their capabilities for further antibody attachment. Commonly applied verification tools for the detection of the trapped antibodies include impedance spectroscopy (IS), atomic fluorescence microscopy (AFM), electrophoresis (EP), enzyme linked immunosorbent assays (ELISA), quartz crystal microbalance (QCM) and infrared spectroscopy (IR). Matrix assisted laser desorption/ionization-time-offlight mass spectrometry (MALDI-TOF/MS) is also a useful tool for proving the success of new antibody fixing procedures. Immobilization techniques have been improved concerning their reproducibility, binding capacity and high specificity. In this review, recent developments of antibody (Ab) immobilization are summarized, the individual applications are mentioned, advantages and disadvantages are discussed in detail.