title: Electropolymerized self-assembled layer on gold nanoparticles: detection of inducible nitric oxide synthase in neuronal cell culture.
abstract: Novel nanostructures of gold nanoparticle (AuNP) encapsulated-conductive polymer have been developed to study biosensor probe materials and utilized to detect the concentration of inducible nitric oxide synthase (iNOS). A 2,2':5',5″-terthiophene-3'-benzoic acid (TTBA) monomer was synthesized and self-assembled on gold nanoparticles (AuNPs). The size effects of the AuNPs and TTBA monomer film thickness on the electrode conductivity were examined. Anti-iNOS antibody was covalently bound on an encapsulated-AuNPs polymer layer with self-assembled TTBA. The immunocomplex formation between iNOS and anti-iNOS was directly observed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). This study looked at the applicability of the self-assembled TTBA layer where the results indicated an efficient electrochemical response toward iNOS. The calibration plot of the current response vs. iNOS concentration exhibited a linear relationship in the range of 0.001-0.02 μg/mL. The calibration sensitivity of iNOS was 59.4 ± 0.3 mV/μg mL(-1). The detection limit of iNOS was determined to be 0.20 ± 0.04 ng/mL based on five time measurements (95% confidence level, k = 3, n = 5). Further results show that AuNP-encapsulated conductive polymers are good nanostructured materials as biosensor probes and have a potential application in cell biosensors.
authors: Department of Chemistry and Institute of Innovative BioPhysio Sensor Technology, Pusan National University, Busan, Korea.
authors: Wei Choon Alvin
authors: WC
authors: Koh
authors: Pranjal
authors: P
authors: Chandra
authors: Dong-Min
authors: DM
authors: Kim
authors: Yoon-Bo
authors: YB
authors: Shim
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry / Q000378:metabolism*; D019817:Benzoic Acid / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D018929:Cell Culture Techniques; D058266:Dielectric Spectroscopy; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000032:analysis* / Q000378:metabolism; D058105:Polymerization; D011199:Potentiometry; D012680:Sensitivity and Specificity; D013876:Thiophenes / Q000737:chemistry
chemical_list: D055910:Antibodies, Immobilized; D013876:Thiophenes; C019101:alpha-terthienyl; D006046:Gold; D019817:Benzoic Acid; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II