Femtomolar immunoassay based on coupling gold nanoparticle enlargement with square wave stripping voltammetry

Abstract The enhancement in sensitivity for an electrochemical immunoassay by the autocatalytic deposition of Au3+ onto gold nanoparticles has been studied. By coupling the autocatalytic deposition with square-wave stripping voltammetry, enlarged gold nanoparticles labeled on goat anti-rabbit immunoglobulin G (GaRIgG-Au) and, thus, the rabbit immunoglobulin G (RIgG) analyte could be determined quantitatively. A variety of variables, such as concentration of AuCl4−, the reducing agent used, the duration of autocatalytic deposition, and parameters for the stripping analysis were optimized. From a calibration graph over a broad dynamic range of concentrations (1–500 pg mL−1; R2 = 0.9975) a very low detection limit, 0.25 pg mL−1 (1.6 fM), which is three orders of magnitude lower than that obtained by a conventional immunoassay using the same gold nanoparticle labels was obtained; this finding confirms applicability and effectiveness of our method of enhancing the sensitivity of gold nanoparticle label-based sandwich immunoassays. The reliability of this method was confirmed by the rather low values of RSD (2.82%, n = 11; 2.44%, n = 9) obtained for assays of a blank solution and for 0.02 ng mL−1 RIgG solution, respectively.

[1]  David J. Newman,et al.  Principles and Practice of Immunoassay , 1991, Palgrave Macmillan UK.

[2]  I Alexandre,et al.  Colorimetric silver detection of DNA microarrays. , 2001, Analytical biochemistry.

[3]  K R Rogers,et al.  Sol-gel-derived thick-film amperometric immunosensors. , 1998, Analytical chemistry.

[4]  S Alegret,et al.  Flow injection immunoanalysis based on a magnetoimmunosensor system. , 1998, Analytical chemistry.

[5]  J. Martin,et al.  Counting of single protein molecules at interfaces and application of this technique in early-stage diagnosis. , 1998, Analytical chemistry.

[6]  V. Vanyukov,et al.  Determination of Gold by Stripping Voltammetry Using a Modified Carbon Paste Electrode , 2002 .

[7]  M. Natan,et al.  Colloidal Au-enhanced surface plasmon resonance immunosensing. , 1998, Analytical chemistry.

[8]  Joseph Wang,et al.  Metal nanoparticle-based electrochemical stripping potentiometric detection of DNA hybridization. , 2001, Analytical chemistry.

[9]  L Orci,et al.  Ultrastructural localization of intracellular antigens by the use of protein A-gold complex. , 1978, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[10]  M. Porter,et al.  Immunoassay readout method using extrinsic Raman labels adsorbed on immunogold colloids. , 1999, Analytical chemistry.

[11]  J. Storhoff,et al.  Selective colorimetric detection of polynucleotides based on the distance-dependent optical properties of gold nanoparticles. , 1997, Science.

[12]  C. Mirkin,et al.  Nanoparticles with Raman spectroscopic fingerprints for DNA and RNA detection. , 2002, Science.

[13]  C. H. Liu,et al.  Amperometric immunosensors based on protein A coupled polyaniline-perfluorosulfonated ionomer composite electrodes. , 2000, Analytical chemistry.

[14]  Zhanfang Ma,et al.  Naked-eye sensitive detection of immunoglubulin G by enlargement of Au nanoparticles in vitro. , 2002, Angewandte Chemie.

[15]  B. Limoges,et al.  An electrochemical metalloimmunoassay based on a colloidal gold label. , 2000, Analytical chemistry.

[16]  Joseph Wang,et al.  Silver-Enhanced Colloidal Gold Electrochemical Stripping Detection of DNA Hybridization , 2001 .

[17]  D. Barceló,et al.  Competitive flow immunoassay with fluorescence detection for determination of 4-nitrophenol , 2001 .

[18]  Hsuan‐Jung Huang,et al.  Immunoassay with a microtiter plate incorporated multichannel electrochemical detection system. , 2002, Analytical chemistry.

[19]  R. Brown,et al.  Employment of a phenoxy-substituted acridinium ester as a long-lived chemiluminescent indicator of glucose oxidase activity and its application in an alkaline phosphatase amplification cascade immunoassay. , 1998, Analytical biochemistry.

[20]  A. Schuurs,et al.  Sol particle immunoassay (SPIA). , 1980, Journal of immunoassay.

[21]  Jun Wang,et al.  Amplified voltammetric detection of DNA hybridization via oxidation of ferrocene caps on gold nanoparticle/streptavidin conjugates. , 2003, Analytical chemistry.

[22]  A. Schuurs,et al.  A homogeneous sol particle immunoassay for human chorionic gonadotrophin using monoclonal antibodies. , 1983, Journal of immunological methods.

[23]  S. Alegret,et al.  Amperometric immunosensors based on rigid conducting immunocomposites. , 1997, Analytical chemistry.

[24]  C. Mirkin,et al.  Scanometric DNA array detection with nanoparticle probes. , 2000, Science.

[25]  Ronen Polsky,et al.  Magnetically-induced solid-state electrochemical detection of DNA hybridization. , 2002, Journal of the American Chemical Society.

[26]  I. Willner,et al.  Amplified detection of DNA and analysis of single-base mismatches by the catalyzed deposition of gold on Au-nanoparticles. , 2001, The Analyst.

[27]  Takehiko Kitamori,et al.  Ultrasensitive heterogeneous immunoassay using photothermal deflection spectroscopy , 1993 .