Abstract
An improved biomonitoring system for the analysis of 2,4,6-trichlorophenol (TCP) in urine samples has been developed. The principle of the biosensor device is the detection of laser-induced fluorescence (LIF) in single microdroplets by a homogeneous quenching fluorescence immunoassay (QFIA). The competitive immunoassay occurs in microdroplets (d = 58,4 μm) produced by a piezoelectric generator system with 10-μm-diameter orifice. A continuous Ar ion laser (488 nm) excites the fluorescent tracer; its fluorescence is detected by a spectrometer attached to a 512 × 512 cooled, charge-coupled device camera. Fluorescence is quenched by specific binding of TCP polyclonal antibodies to the fluorescent tracer (hapten A-fluorescein); the quenching effect is diminished by the presence of the analyte. Thus, an increase in the signal is produced in a positive dose-dependent manner when TCP is present in the sample. In 10 mM PBS buffer, the IC50 of the LIF-microdroplet QFIA is 0.45 μg L-1 reaching a LOD of 0.04 μg L-1. The QFIA with the same reagents performed in microtiter plate format achieved a LOD of 0.36 μg L-1 in buffer solution. Performance in human urine was similar to that observed in the buffer. A LOD of 1.6 μg L-1, with a dynamic range between 4 and 149.5 μg L-1 in urine, was obtained without any sample treatment other than dilution with the assay buffer. The detectability achieved is sufficient for occupational exposure risk assessment.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 83-90 |
| Number of pages | 8 |
| Journal | Analytical Chemistry |
| Volume | 75 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2003 |
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ASJC Scopus subject areas
- Analytical Chemistry
Cite this
Competitive quenching fluorescence immunoassay for chlorophenols based on laser-induced fluorescence detection in microdroplets. / Nichkova, Mikaela; Feng, Jun; Sanchez-Baeza, Francisco; Marco, M. Pilar; Hammock, Bruce D.; Kennedy, Ian M.
In: Analytical Chemistry, Vol. 75, No. 1, 01.01.2003, p. 83-90.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Competitive quenching fluorescence immunoassay for chlorophenols based on laser-induced fluorescence detection in microdroplets
AU - Nichkova, Mikaela
AU - Feng, Jun
AU - Sanchez-Baeza, Francisco
AU - Marco, M. Pilar
AU - Hammock, Bruce D.
AU - Kennedy, Ian M.
PY - 2003/1/1
Y1 - 2003/1/1
N2 - An improved biomonitoring system for the analysis of 2,4,6-trichlorophenol (TCP) in urine samples has been developed. The principle of the biosensor device is the detection of laser-induced fluorescence (LIF) in single microdroplets by a homogeneous quenching fluorescence immunoassay (QFIA). The competitive immunoassay occurs in microdroplets (d = 58,4 μm) produced by a piezoelectric generator system with 10-μm-diameter orifice. A continuous Ar ion laser (488 nm) excites the fluorescent tracer; its fluorescence is detected by a spectrometer attached to a 512 × 512 cooled, charge-coupled device camera. Fluorescence is quenched by specific binding of TCP polyclonal antibodies to the fluorescent tracer (hapten A-fluorescein); the quenching effect is diminished by the presence of the analyte. Thus, an increase in the signal is produced in a positive dose-dependent manner when TCP is present in the sample. In 10 mM PBS buffer, the IC50 of the LIF-microdroplet QFIA is 0.45 μg L-1 reaching a LOD of 0.04 μg L-1. The QFIA with the same reagents performed in microtiter plate format achieved a LOD of 0.36 μg L-1 in buffer solution. Performance in human urine was similar to that observed in the buffer. A LOD of 1.6 μg L-1, with a dynamic range between 4 and 149.5 μg L-1 in urine, was obtained without any sample treatment other than dilution with the assay buffer. The detectability achieved is sufficient for occupational exposure risk assessment.
AB - An improved biomonitoring system for the analysis of 2,4,6-trichlorophenol (TCP) in urine samples has been developed. The principle of the biosensor device is the detection of laser-induced fluorescence (LIF) in single microdroplets by a homogeneous quenching fluorescence immunoassay (QFIA). The competitive immunoassay occurs in microdroplets (d = 58,4 μm) produced by a piezoelectric generator system with 10-μm-diameter orifice. A continuous Ar ion laser (488 nm) excites the fluorescent tracer; its fluorescence is detected by a spectrometer attached to a 512 × 512 cooled, charge-coupled device camera. Fluorescence is quenched by specific binding of TCP polyclonal antibodies to the fluorescent tracer (hapten A-fluorescein); the quenching effect is diminished by the presence of the analyte. Thus, an increase in the signal is produced in a positive dose-dependent manner when TCP is present in the sample. In 10 mM PBS buffer, the IC50 of the LIF-microdroplet QFIA is 0.45 μg L-1 reaching a LOD of 0.04 μg L-1. The QFIA with the same reagents performed in microtiter plate format achieved a LOD of 0.36 μg L-1 in buffer solution. Performance in human urine was similar to that observed in the buffer. A LOD of 1.6 μg L-1, with a dynamic range between 4 and 149.5 μg L-1 in urine, was obtained without any sample treatment other than dilution with the assay buffer. The detectability achieved is sufficient for occupational exposure risk assessment.
UR - http://www.scopus.com/inward/record.url?scp=0037235785&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037235785&partnerID=8YFLogxK
U2 - 10.1021/ac025933n
DO - 10.1021/ac025933n
M3 - Article
C2 - 12530822
AN - SCOPUS:0037235785
VL - 75
SP - 83
EP - 90
JO - Analytical Chemistry
JF - Analytical Chemistry
SN - 0003-2700
IS - 1
ER -