| In this paper, the feasibility of application of immunosensor to determine the contamination in the compost system is basically reviewed. With the work we have accomplished by far, liposome immunosensor and immunoassyas which is used to detect the pollutant in the compost system were studied.Composting technology is applied to disposal of the municipal solid waste increasingly. With the enhancement of the demand of environment quality, there should be a set of detecting methods to match the correlative standard of environment protection. Due to the complexity, diversification and uncertain characteristics of the complex compost system, the commonly used analytical methods , such as spectrophotometry,gas chromatography and high performance liquid chromatography (HPLC) based on the absorbance spectra, are probably interfered by the interference of substrate turbidity and light disturbance, and the pretreatment of the samples is cumbrous and time-consuming, and the instruments are expensive and ponderous. However, biosensor is known for its superior sensitivity, stability, reusability, selectivity, portablity and other obvious advantages. The operation efficiency of compost system will be improved much if biosensor is applied to detect the pollutant in compost.First , a liposome immunosensor was developed and used to analyze the concentration of toxicants in compost extracts based on electrochemical polymerization. A"sandwich-type"immunosensor for the determination of picloram in water environment was developed based on the immunoliposomes prepared by crosslinking rabbit antibody against picloram (anti-picloram) and potassium ferrocyanide-encapsulated liposomes with glutaraldehyde. The working conditions including modification components on the electrode were optimized. The best performance is obtained using 0.5% of Nafion, 10 mg/mL of multiwalled carbon nanotubes (MWCNTs) and 50μg/mL of anti-picloram. The preparation and detection process of immunosensor was as follows. Cyclic voltammetry was applied to urge the electrochemical polymerization of 3, 4-ethylenedioxythiophene (EDOT) and the anti-picloram was immobilized on the modified glassy carbon electrode (GCE). Then the electrode was incubated with the analytes and immunoliposomes sequentially. The bound liposomes were lysed with TritonX-100, and square-wave voltammetry was applied to determine current response of picloram concentration. The whole process was able to be completed in 70 min. The immunosensor has good reproductivity after being soaked in 0.1 mol/Lof H3PO4 in 5 min. The result shows that lower detection limit for picloram is 10-10 mol/L with linear range of 10-10～10-4 mol/L, which meet the detection requirement of picloram for the safety of drinking water.Two haptens of quinclorac(Q), 6-[(3,7-dichloro-8-quinolino-formacyl) amino-hexanoic acid (QC) and 4-[(3,7-dichloro-8-quinolino-formamino)] butanoic acid (QB), were synthesized by using quinclorac and amino-hexanoic acid or amino-butanoic acid as original materials. These two haptens and quinclorac were separately conjugated to bovine serum albumin (BSA) with the modified active ester method. As a result of the study, the combining proportion of Q-BSA, QC-BSA and QB-BSA is 1:1,1:9,1:4 respectively, the immunogenicity of QC-BSA is better.In the research, liposome was prepared with absolute phosphatide by methods of film-decentralization, bath sonication and ether injection. The effects of these preparations are analysed and compared. As a result, the stability of the liposome prepared by film-decentralization is better. The liposome of small sizes could be prepared by combining the methods of extrusion through polycarbonate membranes and bath sonication. The liquid encapsulation efficiency of liposome prepared by methods of bath sonication and ether injection is low, so they are not fit for preparation of liposome which encapsulated the liquid reagent.
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