title: Using capacitance measurements as the detection method in antigen-containing layer-by-layer films for biosensing.
abstract: The layer-by-layer technique is employed here to immobilize antigen-containing liposomes, so-called proteoliposomes, onto Au-interdigitated substrates, which are capable of molecular recognition of anti-pasteurellosis antibodies. Detection was carried out using a novel strategy entirely based upon capacitance measurements, and to enhance sensitivity, we combine the response of three different sensing units in a similar procedure used for taste sensors. With the three-electrode array immunoglobulin G (IgG) against pasteurellosis is detected at concentrations as low as nanograms per milliliter. Furthermore, because of the molecular recognition capability, a distinction can be made between specific and nonspecific IgG. The concepts behind the biosensors reported here may have a large impact for clinical tests, as the procedures to detect the antibody take only a few minutes and the biosensors are relatively low cost.
authors.affiliation: IFSC, Universidade de São Paulo, CP 369, 13566-590, São Carlos, SP, Brazil. zuco@if.sc.usp.br
authors.forename: Valtencir
authors.initials: V
authors.lastname: Zucolotto
authors.forename: Katia R P
authors.initials: KR
authors.lastname: Daghastanli
authors.forename: Caio O
authors.initials: CO
authors.lastname: Hayasaka
authors.forename: Antonio
authors.initials: A
authors.lastname: Riul
authors.forename: Pietro
authors.initials: P
authors.lastname: Ciancaglini
authors.forename: Osvaldo N
authors.initials: ON
authors.lastname: Oliveira
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000941:Antigens / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods*; D025802:Electric Capacitance; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D010326:Pasteurella Infections / Q000175:diagnosis*; D040081:Protein Array Analysis / Q000379:methods*; D011510:Proteolipids / Q000737:chemistry
chemical_list: D000907:Antibodies, Bacterial; D000941:Antigens; D007074:Immunoglobulin G; D011510:Proteolipids; C020485:proteoliposomes; D006046:Gold