Simultaneous Lateral Flow Immunoassay for Multi-Class Chemical Contaminants in Maize and Peanut with One-Stop Sample Preparation

Abstract

Multi-class chemical contaminants, such as pesticides and mycotoxins, are recognized as the major risk factors in agro products. It is thus necessary to develop rapid and simple sensing methods to fulfill the on-site monitoring of multi-class chemical contaminants with different physicochemical properties. Herein, a lateral flow immunoassay via time-resolved fluorescence was developed for the rapid, on-site, simultaneous, and quantitative sensing aflatoxin B1 (AFB1), zearalenone (ZEA), and chlorothalonil (CTN) in maize and peanut. The sample preparation was optimized to a single step, combining the grinding and extraction. Under optimal conditions, the sensing method lowered the limits of detection (LOD) to 0.16, 0.52, and 1.21 µg/kg in maize and 0.18, 0.57, and 1.47 µg/kg in peanut with an analytical range of 0.48–20, 1.56–200, and 3.63–300 µg/kg for AFB1, ZEA and CTN, respectively. The protocol could be completed within 15 min, including sample preparation and lateral flow immunoassay. The recovery range was 83.24–110.80%. An excellent correlation was observed between this approach and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for mycotoxins and gas chromatography-tandem mass spectrometry (GC-MS/MS) for pesticide in maize and peanut. This work could be applied in on-site multi-class sensing for food safety.

Development of Time-Resolved Fluorescence Immunochromatographic Assays for Simultaneously Detecting Tylosin and Tilmicosin in Milk in Group-Screening Manner

“…Europium-chelated fluorescent microspheres with carboxyl activated group were used to conjugate the monoclonal antibody. Based on the existing research results [33,34], the amount of activated microspheres (10%, 100 nm) was fixed at 25 µL, and the amount of conjugated monoclonal antibody was optimized at 5-100 µg according to the quality of different antibodies. The different standard curves were established based on the fluorescent microspheres with different monoclonal antibodies.…”

Time-Resolved Fluorescence Immunochromatography Assay (TRFICA) for Aflatoxin: Aiming at Increasing Strip Method Sensitivity

“…The average recovery was 73-95% with a relative standard deviation of <9.08% (Sun et al, 2018). Wang et al (2019) developed a TRFICA for AFB 1 detection with a linear detection range of 0.48-20 µg/kg and a LOD of 0.18 µg/kg in peanut. The recovery range was 83.24-110.80% (Wang et al, 2019).…”

An Open Sandwich Immunochromatography for Non-competitive Detection of Small Antigens

“…competitive ICs are reported and used for detecting small compounds such as mycotoxins 2,3 , pesticides 4 and antibiotics. 5 Competitive immunoassay involves only one epitope in the target and can detect small target molecules.…”