Developing a fast, accurate, and simple detection method for food allergens is imperative to prevent food allergy. In this study, an on–off-on photoelectrochemical (PEC) aptasensor with dual-signal amplification was constructed based on a covalent organic frame (COF) film to detect β-lactoglobulin (BLG) and Ara h1. Specifically, a uniform and stable TFTA COF film was in situ grown as a PEC signifier on the surface of an indium tin oxide (ITO) electrode. BLG recognition triggered enzyme-assisted circular signal amplification to introduce non-conductive SiO 2 -modified DNA (S0) to the platform, effectively quenching the PEC signal for ultra-sensitive detection of BLG. Upon adding Ara h1, SiO 2 -DNA was released from the sensing platform to restore the PEC signal, and hemin was added to form a G-quadruplex/hemin compound for secondary signal amplification. Thus, sensitive detections of BLG and Ara h1 were achieved with low detection limits (18 ng/mL for BLG and 2.6 ng/mL for Ara h1) and wide linear ranges (0.05–5 µg/mL for BLG and 0.01–0.2 µg/mL for Ara h1). The dual-amplification and dual-target-responsive PEC aptasensor provides a new idea to develop PEC analysis methods for multi-targets in food and environmental monitoring.
Shuo Qi,Anqi Sun,Xiaoze Dong,Yuhan Sun,Minwei Qin,Ning Ding,Yin Zhang,Zhouping Wang
Food allergy is a serious immune allergy reaction, that has attracted public attention all over the world due to the increasing incidence. Ara h1, the most abundant allergenic protein in peanuts, has been identified as a biomarker of peanut allergen. Therefore, a sensitive, efficient method for Ara h1 detection is urgently needed to protect allergy sufferers. In this study, a simple and efficient fluorescent aptasensor was proposed for ultrasensitive and rapid detection of peanut allergen Ara h1. The aptamer against Ara h1 was conjugated onto the surface of high-stable perovskite nanocrystal (PNCs) to serve as the fluorescence-labeled recognition probe as well as the signal probe , while the magnetic nanoparticles Fe 3 O 4 (MNPs) were functionalized with the aptamer complementary DNA (cDNA) as the separation probe. The high-stable PNCs-labeled aptasensor [email protected] gives the combined merits of the extraordinary optical properties of PNCs, the efficient magnetic separation capability of MNPs as well as the high specificity of aptamers. The developed high-stable PNCs-labeled aptasensor exhibited excellent linearity (0.1–100 ng/mL), and low limit of detection (0.04 ng/mL). The aptasensor was successfully applied for the determination of Ara h1 in food samples, implying great potential in the field of allergen assay.
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