Development of Direct ELISA for the Determination of 4-Nonylphenol and Octylphenol

Abstract

Development of direct competitive enzyme-linked immunoadsorbent assays (ELISAs) based on polyclonal and monoclonal antibodies raised against 4-n-alkylphenol hapten mimics is described. A strong tendency to recognize 4-nonylphenol (NP) and 4-octylphenol (OP) as a total analyte amount was indicated by cross-reactivity pattern established for two polyclonal antibodies. These antibodies were employed for development of class-selective assays exhibiting IC(50) values around 40 microg.L(-1) for technical 4-NP. Specificity of the monoclonal antibody 4H6 and additional two polyclonal antibodies allowed sensitive detection of linear long-chain forms of 4-n-alkylphenols (4-n-AP). The assays incorporating these antibodies offer a potential for detecting the minor fraction of NP/OP isomer spectrum having IC(50) = 11.5 microg.L(-1) for 4-n-NP. No cross-reactivity interference was indicated for linear alkylbenzene sulfonates and phenolic compounds. To interpret the measured data in terms of analytical equivalents, a reliable relationship between the assay responses and AP content of contaminated samples should be verified and validated.

Trace analysis of contraceptive drug levonorgestrel in wastewater samples by a newly developed indirect competitive enzyme-linked immunosorbent assay (ELISA) coupled with solid phase extraction

“…However, chromatographic methods could not reach the trace levels in the waters without enrichment step and most of them have drawbacks such as long performing time, tedious sample preparation and expensive instrument. Immunochemical techniques, especially enzyme-linked immunosorbent assay (ELISA), with the features of high sensitivity and specificity, inexpensive instrumentation, simple sample preparation, small sample volumes and rapid analysis have been widely used in environmental analysis [15][16][17][18].…”

Production and characterisation of monoclonal antibodies for the detection of AOZ, a tissue bound metabolite of furazolidone

“…Monoclonal antibodies represent homogeneous antibody entities that have identical affinity and specificity to an antigen. Thus, mono- In previous years, this laboratory has successfully produced monoclonal antibodies against herbicides, 2,4-dichlorophenoxyacetic acid (Franek et al,1994), atrazine (Deng et al, 1999), estrogenic disruptor nonylphenol (Zeravik et al, 2004), sulphonylureas and triazines (Kolar et al, 2002) and utilised them in environmental and food analysis. The immunogen based on the 3-carboxyphenyl-AOZ (CP AOZ) hapten, previously used for the preparation of rabbit antibodies (Cooper et al, 2004a), was utilised for the production of monoclonal antibodies in this work.…”

An Immunoassay for Dibutyl Phthalate Based on Direct Hapten Linkage to the Polystyrene Surface of Microtiter Plates

“…Standards and samples were run in triplicate wells, and the mean absorbance values were processed. Standard curves were obtained by plotting absorbance against the logarithm of analyte concentration and fitted with a logistic four-parameter equation y  = ( A − D )/[1+( x / C ) B ]+ D , where A is the absorbance value with no analyte present, B is the slope near the midpoint inhibition concentration, C is the concentration of analyte giving 50% inhibition (IC 50 ), and D is the minimum absorbance value at infinite concentration of the analyte [20], [21]. Dynamic range was established between the concentrations producing 20% and 80% inhibition (IC 20 –IC 80 or 80%–20% of the maximum response).…”