A capillary-based amperometric flow immunoassay for 2,4,6-trichlorophenol.

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biochemistry

Background:

• 2,4,6-trichlorophenol (2,4,6-TCP) is a pollutant requiring sensitive detection methods.
• Existing methods for TCP detection can be time-consuming or require complex instrumentation.

Purpose of the Study:

• To develop and compare two capillary-based heterogeneous competitive flow immunoassay formats for 2,4,6-TCP determination.
• To evaluate the sensitivity, speed, and robustness of the developed assays in various water matrices.

Main Methods:

• Development of capillary flow injection immunoassay (CFIIA) and capillary sequential injection immunoassay (CSIIA).
• Utilized a beta-galactosidase labeled analyte derivative and anti-TCP antibody competition.
• Employed a glass capillary with immobilized protein A for antibody-bound fraction separation.
• Enzymatic detection of 4-aminophenol (4-AP) via 4-aminophenyl-beta-D-galactoside (4-APG) substrate.

Main Results:

• CFIIA and CSIIA formats achieved IC50 values of 1.41±0.03 and 1.64±0.07 µg L⁻¹, respectively.
• Detection limits were as low as 0.2 µg L⁻¹ for CFIIA and 0.4 µg L⁻¹ for CSIIA.
• Sample throughputs were 6 h⁻¹ for CFIIA and 4 h⁻¹ for CSIIA, with minimal interference from other chlorophenols.

Conclusions:

• Both CFIIA and CSIIA are effective for the rapid screening of 2,4,6-TCP at low concentrations.
• The assays demonstrate good performance in various water samples, with minor matrix effects observed.
• These capillary-based immunoassays offer a promising alternative for environmental monitoring of chlorophenols.