Development of an Enzyme-Linked Immunosorbent Assay to Carbaryl. 2. Assay Optimization and Application to the Analysis of Water Samples

Abstract

The effect of several physicochemical factors on the analytical characteristics of an immunoassay to carbaryl has been studied and this information used to optimize the assay. The immunoassay is based on the LIB-CNH36 monoclonal antibody (MAb) and employs a heterologous coating conjugate. The optimized enzyme-linked immunosorbent assay (ELISA), performed in a high salt concentration buffer with bovine serum albumin instead of Tween 20, has a carbaryl I 50 of 0.058 ppb and a detection limit of 0.010 ppb, which means a 4-fold improvement in the assay sensitivity with respect to the nonoptimized conditions. The assay proved to be very specific for carbaryl since not even 1-naphthol, the main carbaryl metabolite, was recognized. Water samples with very different conductivities were spiked with carbaryl at 0.05, 0.1, and 0.5 ppb and directly analyzed by the developed ELISA. The mean recovery was 112%, and the mean coefficient of variation was 10.7%, which proves the suitability of the method to determine carbaryl in waters at such low levels.

Love Wave Immunosensor for the Detection of Carbaryl Pesticide

“…On the basis of these analytical parameters, the LW immunosensor is more sensitive (around ten-fold) than the one reported for the same compound using the surface plasmon resonance (SPR) transduction principle [ 17 ], where nearly the same immunoreagents were employed. However, it is still one order of magnitude less sensitive than the ELISA's one [ 18 ]. It is also important to mention that this ELISA employed a different conjugate-MAb pair, which provided higher signal responses than BSA-CNH-LIB-CNH45 pair, but does not allow regeneration [ 1 ].…”

Development of Monoclonal Antibody‐based Enzyme‐linked Immunosorbent Assay to the Estrogen Diethylstilbestrol

“…Biochemical interactions with a predominant hydrophobic component are generally favoured by increasing the ionic strength of the reaction medium, while this increase exerts a detrimental effect on interactions where ionic forces prevail. 34 Therefore, the interaction between the antibody and DES-CP or DES, which has an important electrostatic component, could be adversely affected by high salt concentrations in the assay buffer. A practical aspect was also considered selecting the optimum buffer salt concentration within the range (0.5-2)×PBS.…”

Application of commercially available fenitrothion-ELISA kit for soil residue analysis

“…ELISA is highly regarded by many researchers for its high precision and good recovery results. [3][4][5][6] The methodological work using commercially produced ELISA kits is simple and requires no complicated clean-up steps, utilizes less harmful solvents, and is feasible for many samples. ELISA assay is considered to be valuable as a screening tool for identifying and categorizing large numbers of samples before decisive GC and HPLC analyses.…”