Article

Metal particle-enhanced fluorescent immunoassays on metal mirrors. Anal Biochem

Department of Cell Biology and Anatomy, The University of Calgary, Calgary, Alberta, Canada
Analytical Biochemistry (Impact Factor: 2.22). 05/2007; 363(2):239-45. DOI: 10.1016/j.ab.2007.01.030
Source: PubMed

ABSTRACT

We present fluoroimmunoassays on plain metal-coated surfaces (metal mirrors) enhanced by metal nanoparticles (silver island films [SIFs]). Metal mirrors (aluminum, gold, or silver protected with a thin silica layer) were coated with SIFs, and an immunoassay (model assay for rabbit immunoglobulin G or myoglobin immunoassay) was performed on this surface using fluorescently labeled antibodies. Our results showed that SIFs alone (on glass surface not coated with metal) enhance the immunoassay signal approximately 3- to 10-fold. Using a metal mirror instead of glass as support for SIFs results in up to 50-fold signal enhancement.

Download full-text

Full-text

Available from: Joseph R Lakowicz
  • Source
    • "However; these techniques are complicate multistage processes, tedious and time consuming. Matveena et al. [27] has reported a silver island film (SIF) based fluorescence immunosensor for the cardiac Mb detection [15]. But, due to the non-homogeneous nature of SIF it has provided deviations in assay readings, which makes it unfavorable for the precise Mb detection. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We report, a comprehensive physical and biointerfacial electrochemical characteristics of electrodeposited poly(pyrrole-co-pyrrolepropylic acid) (PPy-PPa) copolymer film on the reduced graphene oxide (RGO) sheets attached over a silane modified indium-tin-oxide coated glass, for biosensing applications. The highly specific cardiac myoglobin protein antibody, Ab-cMb, has been covalently immobilized on the copolymer film through its pendent carboxyl group by carbodiimide coupling reaction. The factor ‘n’ describing divergence of the system from ideal capacitor characteristics exhibits a low value (n = 0.59) in a constant phase element of the impedance. This low value of ‘n’ showing a porous rough microstructure of PPy-PPa film on RGO exhibiting a diffusive characteristic that has been replaced by dominant charge transfer characteristic (Ret) with n = 0.78 on biomolecular immobilization and subsequent immunoreaction. The bioelectrode exhibits a linear impedance response to human cardiac cMb marker in the range of 10 ng mL−1 to 1 μg mL−1 in phosphate buffer solution (PBS; pH 7.4) at a low frequency region of <10 Hz with a Ret sensitivity of 70.30 Ω cm2 per decade.
    Full-text · Article · Mar 2014 · Electrochimica Acta
  • Source
    • "However; these techniques are complicate multistage processes, tedious and time consuming. Matveena et al. [27] has reported a silver island film (SIF) based fluorescence immunosensor for the cardiac Mb detection [15]. But, due to the non-homogeneous nature of SIF it has provided deviations in assay readings, which makes it unfavorable for the precise Mb detection. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Here we report a platinum (Pt) nanoflowers decorated multiwalled carbon nanotubes (MWNTs)‐graphene hybrid electrode based nonenzymatic sensor for the detection of glucose. MWNTs/graphene hybrid is synthesized by a one step chemical vapor deposition process via an in situ vaporliquidsolid and surface‐catalyzed mechanisms. Electrodeposition of Pt with optimized parameters at room temperature resulted in high density flower like nanostructures of Pt uniformly distributed over the hybrid electrode. Direct oxidation of glucose takes place due to the electrocatalytic property of the Pt nanoflowers resulting in the amperometric detection of glucose in the physiological range at neutral pH. The developed sensor responded linearly to glucose over the range of 1–7 mM (R 2=0.978) with a high sensitivity of 11.06 µA mM−1 cm−2.
    Full-text · Article · Oct 2013 · Electroanalysis
  • Source
    • "Deposition of such large number of thin films requires expensive vacuum deposition systems with relatively low throughput which may become a limiting factor in the ultimate sensor cost [8] [9]. In addition to planar metal layers, nanostructured metal surfaces can also enhance fluorescence signals [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22]. In this case, plasmonic effects lead to substantial enhancement of the local electric fields near the metal surfaces resulting in fluorescence enhancement much beyond that possible with planar metal layers. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we investigate the application of polyelectrolyte multilayer (PEM) coated metal slides in enhancing fluorescence signal. We observed around eight-fold enhancement in fluorescence for protein incubated on PEM coated on aluminium mirror surface with respect to that of functionalized bare glass slides. The fluorescence intensities were also compared with commercially available FAST® slides (Whatman) offering 3D immobilization of proteins and the results were found to be comparable. We also showed that PEM coated on low-cost and commonly available aluminium foils also results in comparable fluorescence enhancement as sputtered aluminium mirrors. Immunoassay was also performed, using model proteins, on aluminium mirror as well as on aluminium foil based devices to confirm the activity of proteins. This work demonstrated the potential of PEMs in the large-scale, roll-to-roll manufacturing of fluorescence enhancements substrates for developing disposable, low-cost devices for fluorescence based diagnostic methods.
    Full-text · Article · Jul 2013 · Sensors and Actuators B Chemical
Show more