title: Development of robust and standardized cantilever sensors based on biotin/NeutrAvidin coupling for antibody detection.
abstract: A cantilever-based protein biosensor has been developed providing a customizable multilayer platform for the detection of antibodies. It consists of a biotin-terminated PEG layer pre-functionalized on the gold-coated cantilever surface, onto which NeutrAvidin is adsorbed through biotin/NeutrAvidin specific binding. NeutrAvidin is used as a bridge layer between the biotin-coated surface and the biotinylated biomolecules, such as biotinylated bovine serum albumin (biotinylated BSA), forming a multilayer sensor for direct antibody capture. The cantilever biosensor has been successfully applied to the detection of mouse anti-BSA (m-IgG) and sheep anti-BSA(s-IgG) antibodies. As expected, the average differential surface stress signals of about 5.7 ± 0.8 × 10(-3) N/m are very similar for BSA/m-IgG and BSA/s-IgG binding, i.e., they are independent of the origin of the antibody. A statistic evaluation of 112 response curves confirms that the multilayer protein cantilever biosensor shows high reproducibility. As a control test, a biotinylated maltose binding protein was used for detecting specificity of IgG, the result shows a signal of bBSA layer in response to antibody is 5.8 × 10(-3) N/m compared to bMBP. The pre-functionalized biotin/PEG cantilever surface is found to show a long shelf-life of at least 40 days and retains its responsivity of above 70% of the signal when stored in PBS buffer at 4 °C. The protein cantilever biosensor represents a rapid, label-free, sensitive and reliable detection technique for a real-time protein assay.
authors.affiliation: Swiss Nano Institute, University of Basel, Basel, Switzerland. jiayun.zhang@unibas.ch
authors.forename: Jiayun
authors.initials: J
authors.lastname: Zhang
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Lang
authors.forename: Felice
authors.initials: F
authors.lastname: Battiston
authors.forename: Natalija
authors.initials: N
authors.lastname: Backmann
authors.forename: Francois
authors.initials: F
authors.lastname: Huber
authors.forename: Christoph
authors.initials: C
authors.lastname: Gerber
mesh_terms: D000818:Animals; D000906:Antibodies / Q000032:analysis*; D000941:Antigens / Q000378:metabolism; D001360:Avidin / Q000378:metabolism*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000592:standards*; D001710:Biotin / Q000378:metabolism*; D019921:Biotinylation; D002417:Cattle; D007074:Immunoglobulin G / Q000032:analysis; D051379:Mice; D012015:Reference Standards; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D000906:Antibodies; D000941:Antigens; D007074:Immunoglobulin G; C093483:neutravidin; D001360:Avidin; D012710:Serum Albumin, Bovine; D001710:Biotin