Advances in the Immunoassays for Detection of Bacillus thuringiensis Crystalline Toxins

Abstract

Insect-resistant genetically modified organisms have been globally commercialized for the last 2 decades. Among them, transgenic crops based on Bacillus thuringiensis crystalline (Cry) toxins are extensively used for commercial agricultural applications. However, less emphasis is laid on quantifying Cry toxins because there might be unforeseen health and environmental concerns. Immunoassays, being the preferred method for detection of Cry toxins, are reviewed in this study. Owing to limitations of traditional colorimetric enzyme-linked immunosorbent assay, the trend of detection strategies shifts to modified immunoassays based on nanomaterials, which provide ultrasensitive detection capacity. This review assessed and compared the properties of the recent advances in immunoassays, including colorimetric, fluorescence, chemiluminescence, surface-enhanced Raman scattering, surface plasmon resonance, and electrochemical approaches. Thus, the ultimate aim of this study is to identify research gaps and infer future prospects of current approaches for the development of novel immunosensors to monitor Cry toxins in food and the environment.

Detection of Bacillus group spores in an aqueous environment using an aptamer based digital photocorrosion biosensor

“…Conventional laboratory methods such as culture [13] and enzyme-linked immunosorbent assay (ELISA) [14], are commonly used for Bt detection, however they suffer from being time consuming, and frequently showing relatively low sensitivity [15]. To overcome the limitations of those methods limitations and ensuring quasi-real time monitoring of BC spores, biosensors based on electrical, optical or piezoelectric transducers have been proposed [16,17]. However, most of them are not easily applicable to automated monitoring of pathogens at remote locations [18].…”

Quantum-Dot-Bead-Based Fluorescence-Linked Immunosorbent Assay for Sensitive Detection of Cry2A Toxin in Cereals Using Nanobodies

“…In addition, Cry toxins are widely introduced into genetically modified (GM) crops for protection against insect pests [ 8 , 9 ]. However, the safety of Cry toxins has not been universally recognized and accepted, and the widespread use of Cry toxins may pose potential threats to the eco-environment and public health [ 10 , 11 ]. Many countries have established mandatory labeling policies for GM products with a threshold level of 0–5% [ 12 ].…”

Flexible electronic materials and devices toward portable immunoassays

“…7,8 The immunoassay approach combines appropriate transducers to convert antibody-antigen interactions into measurable signals, such as pressure, 9,10 temperature, 11,12 electrochemical parameters, [13][14][15] and optical messages. 16,17 Given the benefits provided by portable immunoassays, especially rapid testing, visual detection, and simplicity of use, their application has grown rapidly in a wide range of industries, including healthcare, 18 agriculture, 19 environmental monitoring, 20 and food safety. 21 In recent years, researchers have focused on flexible biosensors for wearable, in-the-moment, and on-site detection.…”