Abstract
A novel potentiometric immunosensor for the detection of adrenal cortical hormones (ACH) has been developed by means of self-assembling immobilization of adrenal cortical hormone antibody (anti-ACH) on a gold electrode-modified gold nanoparticle (Au) and a thiol-containing sol–gel network. A cleaned gold electrode was first immersed in a (3-mercaptopropyl)-trimethoxysilane (MPS) sol–gel solution to assemble a silica sol–gel monolayer, then the silane units were polymerized into a 2D sol–gel network (2D network) by dipping into aqueous NaOH. The second silane layer was formed by immersion back into the MPS solution overnight, and then the gold nanoparticles (nanogold) were chemisorbed onto the thiol groups of the second silane layer. Finally, anti-ACH was adsorbed onto the surface of the gold nanoparticles. The modified process was characterized by electrochemical impedance spectroscopy (EIS). The detection is based on the change in the potentiometric response before and after the antigen–antibody reaction. Using nanogold and 3-MPS as substrates, potentiometric detection at room temperature resulted in a pseudolinear detection range of about 22–1,000 ng mL−1 with a detection limit of 5.2 ng mL−1. Subsequently, several serum samples obtained from medical students with different anxiety extents were analyzed comparing with the ELISA method, and the results demonstrated that the immunoassay meets the demands of psychological analyses.
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References
Storri S, Santoni T, Minunni M, Mascini M (1998) Surface modifications for the development of piezoimmunosensors. Biosens Bioelectron 13:347–357
Mulchandani A, Mulchandani P, Chauhan S, Kaneva I, Chen W (1998) A potentiometric microbial biosensor for direct determination of organophosphate nerve agents. Electroanalysis 10:733–737
Souteyrand E, Martin JR (1994) Direct detection of biomolecules by electrochemical impedance measurements. Sens Actuators B 20:63–69
Mirsky VM, Riepl M, Wolfbeis O (1997) Capacitive monitoring of protein immobilization and antigen-antibody reactions on monomolecular alkylthiol films on gold electrodes. Biosens Bioelectron 12:977–989
Hianik T, Snejdarkova M, Sokolikova L, Meszar E, Krivanek R, Tvarozek V, Novotny I, Wang J (1999) Immunosensors based on supported lipid membranes, protein films and liposomes modified by antibodies. Sens Actuators B 57:201–212
Eckert R, Jeney S, Jorber JKH (1997) Understanding intercellular interactions and adhesion: lessons from studied on protein-matal interactions. Cell Biol Int 21:707–713
Frens G (1973) Controlled nucleation for the regulation of the particle size in monodisperse gold suspensions. Nat Pys Sci 241:20–22
Robertson JW, Cai M, Pemberton JE (2001) Insulating ultrathin silica films formed by a room-temperature sol–gel process. Adv Mater 13:662–667
Cai M, Ho M, Pemberton JE (2000) Surface vibrational spectroscopy of alkylsilane layers covalently bonded to monolayers of (3-mercaptopropyl)trimethoxysilane on Ag substrates. Langmuir 16:3446–3453
Pei R, Cheng Z, Wang E, Yang X (2001) Amplification of antigen-antibody interactions based on biotin labeled protein-streptavidin network complex using impedance spectroscopy. Biosens Bioelectron 16:355–361
Atassi MZ, Van-Oss CJ, Absolom DR (1984) Molecular Immunology, Marcel Dekker, New York
Jiang ZH, Zhang JH (1998) Technology and application of biomolecular immobilization, Chemiscal Industry Press, Beijing
Zhao JG, Henkens RW, Stonehuerner JL, O’Daly JP, Crumbliss AL (1992) Direct electron transfer at horseradish peroxidase—colloidal gold modified electrodes. J Electroanal Chem 327:109–119
Ebato H, Gentry CA, Herton JN, Muller W, Okahata Y, Ringsdorf H, Suci PA (1994) Investigation of specific binding of antifluorescyl antibody and fab to fluorescein lipids in Langmuir-Blodgett deposited films using quartz crystal microbalance methodology. Anal Chem 66:1683–1689
Okahata Y, Kawase M, Niilura K, Ohtake F, Furusawa H, Ebara Y (1998) Kinetic measurements of DNA hybridization on an oligonucleotide-immobilized 27-MHz quartz crystal microbalance. Anal Chem 70:1288–1296
Acknowledgements
Financial support for this work was provided by the National Natural Science Foundation of China (29705001), the Chinese Education Ministry Foundation for excellent young teachers, and the Natural Science Foundation of Chongqing City, China.
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Tang, DQ., Tang, DY. & Tang, DP. Construction of a novel immunoassay for the relationship between anxiety and the development of a primary immune response to adrenal cortical hormone. Bioprocess Biosyst Eng 27, 135–141 (2005). https://doi.org/10.1007/s00449-004-0394-9
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DOI: https://doi.org/10.1007/s00449-004-0394-9