Environmental hormones, also called environmental endocrine-disrupting chemicals (EDCs), are produced by various human activities and environment pollution, and they are composed of industrial chemicals and environmental pollutants. They play a harmful role in breaking the balance of normal physiological metabolism, causing serious diseases and disrupting reproductive development in wildlife and human beings by inhibiting or imitating the action of normal gonadal hormones. Strict controls of maximum residue levels to some environmental hormones in foodstuff have been set up by many countries. Traditional detection methods, due to their high accuracy and maturity, are used extensively, such as HPLC, HPLC–MS, and GC–MS. However, these methods are time consuming and require extraordinary skills of operators, and sometimes they cannot meet the requirements of field testing. Immunoassay has the advantages of high specificity, sensitivity, simplicity, convenience, and the ability to achieve high throughput, playing an irreplaceable role in the field of rapid detection. This review focuses on the antibody production and the development of immunoassays to detect environmental hormones in food and environment. Therefore, estrogen, progesterone, and testosterone are selected as examples to introduce a series of procedures for the detection of environmental hormones including antigen synthesis, antibody production, and antibody-based detection methods.
In recent years, furosemide has been found to be abused in slimming health foods. There is an urgent need for a simpler, faster method for detecting furosemide in slimming health foods. In this study, a rapid, convenient and sensitive lateral flow immunochromatography (LFIA) based on Au nanoparticles (AuNPs) was established for the first time. Under optimal conditions, the qualitative limit of detection (LOD) of the AuNPs-based LFIA was 1.0~1.2 μg/g in slimming health foods with different substrates. AuNPs-LFIA could specifically detect furosemide within 12 min (including sample pretreatment) and be read by the naked eye. The developed AuNPs-LFIA showed high consistency with liquid chromatography with tandem mass spectrometry (LC-MS/MS), and no false positive or false negative results were found in spiked slimming health foods, proving that the AuNPs-LFIA should be accurate and reliable. The AuNPs-LFIA reported here provides a serviceable analytical tool for the on-site detection and rapid initial screening of furosemide for the first time.
In this study novel immunoconjugates were designed, synthesized and then used to develop a rapid, specific and sensitive indirect ELISA method to directly detect residues of 3,5-dinitrosalicyclic acid hydrazide (DNSH), a toxic metabolite of nifursol present in chicken tissues. The hapten DNSHA was first designed and used to covalently couple to BSA to form an immunogen which was immunized to rabbits to produce a polyclonal antibody against DNSH. Furthermore, a novel 3,5-dinitrosalicylic acidovalbumin (DNSA-OVA) immunoconjugate structurally different from DNSHA-OVA was designed and used as a “substructural coating antigen” to improve the sensitivity of an indirect ELISA analysis for a direct DNSH detection. Based on the “substructural coating antigen” concept, an optimized indirect ELISA method was established that exhibited good specificity and high sensitivity for detecting DNSH, with a cross-reactivity of less than 0.1% (excluding the parent compound nifursol), IC50 of 0.217 nmol/mL and detection limit of 0.018 nmol/mL. Finally, a simple and efficient analysis of DNSH samples in chicken tissues showed that the average recovery rate of the indirect ELISA analysis was 82.3%, with the average coefficient of variation 15.9%. Thus, the developed indirect ELISA method exhibited the potential for a rapid detection of DNSH residues in tissue.