Abstract
Currently, detection in microarray bioanalysis is based mainly on the use of organic dyes. To overcome photobleaching and spectral overlaps we applied a new type of fluorophore, crystalline europium-doped gadolinium oxide (Eu:Gd 2O3) nanoparticles, as labels in immunoassay microarrays. The Eu:Gd2O3 nanoparticles synthesized by spray pyrolysis offer narrow red emission, large Stokes shift, photostable laser-induced fluorescence with a long lifetime (1 ms). The amino functionalization of the particles was achieved by poly(L-lysine) (PL) encapsulation. The formation of a stable PL shell was confirmed by TEM analysis, colloidal stability studies, and quantification of the surface reactive amino groups. The PL-encapsulated particles were covalently conjugated to antibodies and successfully applied as reporters in a competitive fluorescence microimmunoassay for phenoxybenzoic acid (PBA), a generic biomarker of human exposure to pyrethroid insecticides. Microarrays were fabricated by microcontact printing of BSA-PBA in line patterns (10 × 10 μm). Confocal fluorescence microscopy combined with internal standard (fluorescein) calibration was used for quantitative measurements. The microarray immunoassay demonstrated a limit of detection of 1.4 μg L -1 PBA. This work suggests the potential application of lanthanide oxide nanoparticles as fluorescent probes in microarray and biosensor technology, immunodiagnostics, and high-throughput screening.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6864-6873 |
| Number of pages | 10 |
| Journal | Analytical Chemistry |
| Volume | 77 |
| Issue number | 21 |
| DOIs | |
| State | Published - Nov 1 2005 |
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ASJC Scopus subject areas
- Analytical Chemistry
Cite this
Microarray immunoassay for phenoxybenzoic acid using polymer encapsulated Eu : Gd2O3 nanoparticles as fluorescent labels. / Nichkova, Mikaela; Dosev, Dosi; Gee, Shirley J.; Hammock, Bruce D.; Kennedy, Ian M.
In: Analytical Chemistry, Vol. 77, No. 21, 01.11.2005, p. 6864-6873.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Microarray immunoassay for phenoxybenzoic acid using polymer encapsulated Eu
T2 - Gd2O3 nanoparticles as fluorescent labels
AU - Nichkova, Mikaela
AU - Dosev, Dosi
AU - Gee, Shirley J.
AU - Hammock, Bruce D.
AU - Kennedy, Ian M.
PY - 2005/11/1
Y1 - 2005/11/1
N2 - Currently, detection in microarray bioanalysis is based mainly on the use of organic dyes. To overcome photobleaching and spectral overlaps we applied a new type of fluorophore, crystalline europium-doped gadolinium oxide (Eu:Gd 2O3) nanoparticles, as labels in immunoassay microarrays. The Eu:Gd2O3 nanoparticles synthesized by spray pyrolysis offer narrow red emission, large Stokes shift, photostable laser-induced fluorescence with a long lifetime (1 ms). The amino functionalization of the particles was achieved by poly(L-lysine) (PL) encapsulation. The formation of a stable PL shell was confirmed by TEM analysis, colloidal stability studies, and quantification of the surface reactive amino groups. The PL-encapsulated particles were covalently conjugated to antibodies and successfully applied as reporters in a competitive fluorescence microimmunoassay for phenoxybenzoic acid (PBA), a generic biomarker of human exposure to pyrethroid insecticides. Microarrays were fabricated by microcontact printing of BSA-PBA in line patterns (10 × 10 μm). Confocal fluorescence microscopy combined with internal standard (fluorescein) calibration was used for quantitative measurements. The microarray immunoassay demonstrated a limit of detection of 1.4 μg L -1 PBA. This work suggests the potential application of lanthanide oxide nanoparticles as fluorescent probes in microarray and biosensor technology, immunodiagnostics, and high-throughput screening.
AB - Currently, detection in microarray bioanalysis is based mainly on the use of organic dyes. To overcome photobleaching and spectral overlaps we applied a new type of fluorophore, crystalline europium-doped gadolinium oxide (Eu:Gd 2O3) nanoparticles, as labels in immunoassay microarrays. The Eu:Gd2O3 nanoparticles synthesized by spray pyrolysis offer narrow red emission, large Stokes shift, photostable laser-induced fluorescence with a long lifetime (1 ms). The amino functionalization of the particles was achieved by poly(L-lysine) (PL) encapsulation. The formation of a stable PL shell was confirmed by TEM analysis, colloidal stability studies, and quantification of the surface reactive amino groups. The PL-encapsulated particles were covalently conjugated to antibodies and successfully applied as reporters in a competitive fluorescence microimmunoassay for phenoxybenzoic acid (PBA), a generic biomarker of human exposure to pyrethroid insecticides. Microarrays were fabricated by microcontact printing of BSA-PBA in line patterns (10 × 10 μm). Confocal fluorescence microscopy combined with internal standard (fluorescein) calibration was used for quantitative measurements. The microarray immunoassay demonstrated a limit of detection of 1.4 μg L -1 PBA. This work suggests the potential application of lanthanide oxide nanoparticles as fluorescent probes in microarray and biosensor technology, immunodiagnostics, and high-throughput screening.
UR - http://www.scopus.com/inward/record.url?scp=27544488699&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=27544488699&partnerID=8YFLogxK
U2 - 10.1021/ac050826p
DO - 10.1021/ac050826p
M3 - Article
C2 - 16255584
AN - SCOPUS:27544488699
VL - 77
SP - 6864
EP - 6873
JO - Analytical Chemistry
JF - Analytical Chemistry
SN - 0003-2700
IS - 21
ER -