title: A reusable piezoelectric immunosensor using antibody-adsorbed magnetic nanocomposite.
abstract: This paper reports a simple, sensitive, and reusable piezoelectric immunosensor using magnetic hydroxyapatite (HAP)/gamma-Fe(2)O(3)/Au nanocomposite. Use of porous HAP nanocrystals embedded with gamma-Fe(2)O(3) and colloidal gold nanoparticles resulted in a multifunctional HAP/gamma-Fe(2)O(3)/Au nanocomposite. Under optimized conditions, the biocompatible nanocomposites were exploited for direct adsorption of large quantities of rabbit anti-human immunoglobulin G antibodies (anti-hIgG) with well-preserved immunoactivity. In a homogeneous bulk solution, the hIgG analytes were captured by the anti-hIgG-derivatized immunocomposites followed by magnetic separation/enrichment onto a bovine serum albumin (BSA)-sealed QCM probe before measuring. This QCM immunosensor can quantitatively determine concentrations of hIgG ranging from approximately 20 to 800 ng/ml, with a detection limit of approximately 15 ng/ml. Moreover, regeneration of the immunosensor can be simply realized by canceling the controllable magnetic field. With the possibility of performing the analysis automatically and considering its ease of use, high sensitivity, and good reusability, this magnetic separation-assisted QCM immunosensor may have great potential to be further tailored as a general and promising alternative for a broad range of practical applications.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Bani
authors.initials: B
authors.lastname: Yan
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jishan
authors.initials: J
authors.lastname: Li
authors.forename: Guoli
authors.initials: G
authors.lastname: Shen
authors.forename: Ruqin
authors.initials: R
authors.lastname: Yu
mesh_terms: D000327:Adsorption; D000818:Animals; D000906:Antibodies / Q000032:analysis* / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D002417:Cattle; D003102:Colloids / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry / Q000276:immunology; D005290:Ferric Compounds / Q000737:chemistry / Q000276:immunology; D006046:Gold / Q000737:chemistry / Q000276:immunology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000276:immunology; D013499:Surface Properties; D013552:Swine; D013997:Time Factors
chemical_list: D000906:Antibodies; D003102:Colloids; D005290:Ferric Compounds; D007074:Immunoglobulin G; C000499:ferric oxide; D012710:Serum Albumin, Bovine; D006046:Gold; D017886:Durapatite