Antibody anti-atrazine

ELP fusion protein (Fig. 9, center). It was shown that picomolar levels of ELP fusion proteins could be purified via ELP coaggregation [47, 48]. The value of this technique was shown by the purification of low levels of ELP fused to an anti-atrazine antibody [49]. 

Immunosorbents have also found applicability in on-line SPE analysis. An antibody is immobilized on to a silica support and used as an affinity ligand to retain targeted analytes. Components not recognized by the antibody are not retained and some degree of selectivity is attained. Recoveries of 87-103% were obtained for atrazine, simazine, DEA, propazine, and terbuthylazine at the 0.2 xgL concentration level when using immunosorbent SPE (80 mg silica and 2 mg anti-atrazine and anti-chlortoluron antibodies) on-line with LC/APcI-MS however, this method is not applicable to DIA (0% recovery). This compound may be better retained when using an... 

Fig. 22.2. The different biocomposite materials (protA-GEB, Av-GEB, Ab-GEB) and the different strategies for the immobilization of anti-atrazine antibodies on the surface of the electrochemical transducer for the electrochemical biosensing of atrazine. Further experimental details can be found in the text (more details are given in Zacco et al.).

Immobilization of anti-atrazine antibody on ProtA-GEB. Add 20 pL of a solution (0.5 pg) of anti-atrazine antibodies onto the polished surface of a ProtA-GEB electrode. Allow the adsorption to proceed at 42°C until dryness (approximately 30 min) under static conditions. 

Fig. 33.1. Competitive immunoassays for the determination of atrazine in spiked orange juice samples, based on dry-assisted affinity immobilization of the anti-atrazine antibodies (0.5 pg) on ProtA(2%)-GEB. The biosensors were incubated with 0.02 pg of atrazine-HRP tracer. In all cases, n — 3.

Strachan, G., S. Grant, D. Learmonth, M. Longstaff, A. Porter, and W. Harris (1998). Binding characteristics of anti-atrazine monoclonal antibodies and their fragments synthesized in bacteria and plants. Biosens. Bioelectron., 13 665-673. 

Anti-atrazine antibodies were coupled to a Si microchip comprising 42 coated porous flow channels. The porous Si layer was achieved by anodizing the channel in 40% HF/96% ethanol (1 1). Detection of atrazine was achieved in a competitive format. The chemiluminescence signal decreased when a known amount of horseradish peroxidase-labeled atrazine was added. This decrease was used to determine the amount of unlabeled atrazine in the sample [1030],... 

Table I. Production of Anti-hydroxyatrazine and Anti-atrazine Monoclonal Antibodies...

Kusharyoto W, Pleiss J, Bachmann TT et al. Mapping of a hapten-binding site Molecular modelling and site-directed mutagenesis study of an anti-atrazine antibody. Protein Engineering 2002 15 233-241. 

Turniansky A., Avnir D., Bronshtein A., Aharonson N., Altstein M. Sol-gel entrapment of monoclonal anti-atrazine antibodies. J. Sol-Gel Sci. Technol. 1996 7 135-143 Vazquez-Lira J.C., Camacho-Frias E., Pena-Alvarez A., Vera-Avila L.E. Preparation and characterization of a sol-gel immnnosorbent doped with 2,4-d antibodies. Chem. Mater. 2003 15 154-161... 

Piezoelectric biosensor arrays for dioxins have been reported, the sensor surfaces using different pentapeptides as biomimetic traps (receptors) and measuring the changes in mass. Recently, a protocol to fabricate acoustic micro-immunosensors based on a QCM was described and used to measure carbofuran or atrazine as antigens on a surface functionalised with monoclonal anti-carbofuran or with anti-atrazine IgG antibodies. A similar antibody-antigen approach for parathion is described in reference (59). 

The mentioned assays led to atrazine residue recoveries between 25 and 1000%, which is a variation that might be due to the high complexity of the sample matrix and the non-homogeneity of the standards used [77]. Improved characteristics were obtained after a better characterization of the used standards [78]. A further improvement was achieved by replacing the anti-humic acid antibodies, used for capturing the analjde, with basic proteins [79,80]. These are easily available and have the advantage that a broader variety of humic acids can be bound therefore, the assay should be independent of the composition of a particular soil. The use of this assay format improved both the sensitivity and signal intensity. 

Immuno-SLM system was successfully apphed as a sample preparation method for 4-nitrophenol and atrazine detection in water and juice samples. Polyclonal anti-4-nitrophenol antibodies were used for SLM immunoper-traction from spiked reagent and wastewater samples [35]. The immuno-SLM was also used for selective pertraction of the popular herbicide atrazine as a model sample from tap and river water samples as well as from orange juice [36]. 

Au electrode was pretreated in the same way as the Quartz immobilized technique before being modified with atrazine hapten using ED AC as the coupling reagent. The modified electrode was used for electrochemical analysis, first without soaking in an antibody solution. Later the electrode was incubated in an anti-cyanazine antibody solution at 35°C using a thermostated water-bath. All cyclic voltammetry experiments were conducted at the same temperature. Other electrochemical immobilization procedures were as recently reported (12,13). 

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