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.

An amperometric nanobiosensor using a biocompatible conjugate for early detection of metastatic cancer cells in biological fluid

“…2,2′:5′,2ʺ-Terthiophene-3′ (p-benzoic acid (TTBA)) was prepared using the Paal-Knorr pyrrole condensation reaction (Koh et al, 2011). Tetrabutylammonium perchlorate (TBAP, electrochemical grade) was purchased from Fluka (USA) and purified according to a general method, followed by drying under vacuum at 1.33 Â 10 À 3 Pa (Chandra et al, 2011a).…”

Advance Diagnosis of Drug Resistance in Cancer: Towards Point-of-Care Electronic Nanodevice

“…While these methods have been applied for the detection of drug resistant cancer cells (DRCC), but they are less sensitive, need extremely trained professionals, and lacks the ability to be miniaturized for the onsite medical detection. In recent years, electrochemical nanosensors are found to be the most promising approach to resolve the issues related to sensitivity, rapidity, selectivity, and ability to be miniaturized [8][9][10][11][12][13][14][15][16][17]. Thus, in biosensorbased detection technologies have been also attempted for the detection of DRCC.…”

Fabrication of a porphyrin-based electrochemical biosensor for detection of nitric oxide released by cancer cells

“…Figure 7 shows the amperometric response of NO released by HeLa cells at an applied potential of 0.6 V on addition of 20 μL of PMA every addition. The NO sensor registered an amperometric current response of 0.0138 nA/μL with a linear correlation coefficient of 0.99571 related to the presence of extracellular NO released upon activation of HeLa cells [55]. The arrows denote PMA addition to the marked concentrations.…”