title: A chelating-bond breaking and re-linking technique for rapid re-immobilization of immune micro-sensors.
abstract: With high sensitivity and specificity to antigen, immune micro-sensors can be used in rapid detection of pathogenic microbial. This study proposes and develops a method for rapidly regeneration of antibody on a resonant micro-cantilever sensor. A nitrilotriacetic acid (NTA) derivative is synthesized with cystine and bromoacetic acid, then added with 2-mercaptoethanol to prepare a mixed self-assembled monolayer (SAM) on Au (111) surface of the cantilever. Ni²⁺ ions are thereafter chelated on the mixed SAM to form a breakable and re-linkable chelating-bond layer. Repeatable cycles of antibody immobilization and erasing are experimentally validated with a detectable marker of synthesized biotinylated poly peptides harboring six histidine residues (named as His-Bio). Two distinguished pathogenic microbial, Escherichia. coli O157:H7 and Bacillus Anthracis, are detected with the rapidly regenerated sensor. The E. coli O157:H7 sensor exhibits a three-time repeated detection to the 10³ CFU/ml concentration microbial. Then, an E. coli O157:H7 sensor is eluted with Tris-HCl (20 mM Tris, 150 mM NaCl, 0.1% Tween 20, pH = 3.0) and rapidly reconstructed into a B. Anthracis sensor by changing the re-immobilized antibody. The cantilever sensor no longer responses to E. coli O157:H7 even in a high concentration of 10⁷ CFU/ml. In contrast, the sensor is experimentally confirmed being resoluble to low concentration B. Anthracis at 10³ spores/ml level. The proposed fast regeneration method is promising in repeatedly or multi-target detection applications of micro/nano immune-sensors, e.g. the resonant micro-cantilevers.
authors: State Key Lab of Transducer Technology, and, Science and Technology on Microsystem Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.
authors: Tiegang
authors: T
authors: Xu
authors: Haitao
authors: H
authors: Yu
authors: Pengchen
authors: P
authors: Xu
authors: Xinxin
authors: X
authors: Li
mesh_terms: D000085:Acetates / Q000737:chemistry; D000906:Antibodies; D000907:Antibodies, Bacterial / Q000276:immunology*; D055910:Antibodies, Immobilized / Q000378:metabolism; D001408:Bacillus anthracis / Q000302:isolation & purification; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D003553:Cystine / Q000737:chemistry; D004867:Equipment Design; D019453:Escherichia coli O157 / Q000302:isolation & purification; D007118:Immunoassay / Q000379:methods; D008623:Mercaptoethanol / Q000737:chemistry; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation / Q000379:methods; D009571:Nitrilotriacetic Acid / Q000138:chemical synthesis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000378:metabolism
chemical_list: D000085:Acetates; D000906:Antibodies; D000907:Antibodies, Bacterial; D055910:Antibodies, Immobilized; D003553:Cystine; D008623:Mercaptoethanol; C016274:bromoacetate; D012822:Silicon Dioxide; D009571:Nitrilotriacetic Acid