Synthesis and electrochemical characterization of myoglobin-antibody protein immobilized self-assembled gold nanoparticles on ITO-glass plate

• Published in: Materials chemistry and physics 2012-01, Vol.132 (1), p.22-28
• Main Authors: Rajesh, Sharma, Vikash, Mishra, Sujeet K., Biradar, Ashok M.
• Format: Article
• Language: English
• Subjects: Acoustic microscopes; Assembly; Carbodiimides; Covalent immobilization; Cyclic voltammetry; Gold; Immunoassay; Joining; Nanoparticles; Protein; Proteins; Self assembly
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2011.10.024

► The Mb-Ab was covalently bonded to carboxyl groups of the mixed MUA and MPA over self-assembled GNPs. ► This assembly on ITO-glass plate was used as an impedimetric immunosensor for myoglobin detection. ► High loading of Mb-Ab, on the GNPs results in a wide range of Mb-Ag detection from 0.01 μg to 1.65 μg mL −1 ► The simple method and wide range of Mb-Ag detection makes this advantageous over other methods. We report a protein immobilized self-assembled monolayer (SAM) of gold nanoparticles (GNPs) on indium-tin-oxide (ITO) coated glass plate. The protein-antibody, Mb-Ab, was covalently immobilized over the self-assembly of GNPs through a mixed SAM of 11-mercapto undecanoic acid (MUA) and 3-mercapto propionic acid (MPA) via carbodiimide coupling reaction using N-(3-dimethylaminopropyl)- N′-ethyl carbodiimide (EDC) and N-hydroxy succinimide (NHS). The whole assembly was constructed on 0.25 cm 2 area of ITO-glass plate (Mb-Ab/MUA-MPA/GNPs/APTES/ITO-glass) and an impedimetric study was carried out for its application in myoglobin detection. This prototype assembly was characterized by scanning electron microscopy, atomic force microscopy and electrochemical techniques. The modified electrode showed an increased electron-transfer resistance on coupling with protein antigen, Mb-Ag, in the presence of a redox probe [Fe(CN) 6] 3−/4−. Its exhibits an electrochemical impedance response to protein myoglobin-antigen, Mb-Ag, concentration in a linear range from 0.01 μg to 1.65 μg mL −1 with a lowest detection limit of 1.4 ng mL −1.