A target-responsive and signal-amplified DNA hydrogel biosensor for visual and quantitative detection of Aflatoxin B1

Haojie Du, School of New Materials and Future Technologies, Beijing Technology and Business University, No.11 Fucheng Road, Haidian District, Beijing 100048, China
Haoyue Liu, School of New Materials and Future Technologies, Beijing Technology and Business University, No.11 Fucheng Road, Haidian District, Beijing 100048, China
Yongshuai Li, School of New Materials and Future Technologies, Beijing Technology and Business University, No.11 Fucheng Road, Haidian District, Beijing 100048, China
Shiyi Wei, School of New Materials and Future Technologies, Beijing Technology and Business University, No.11 Fucheng Road, Haidian District, Beijing 100048, China
Xinning Wang, School of New Materials and Future Technologies, Beijing Technology and Business University, No.11 Fucheng Road, Haidian District, Beijing 100048, China
Yunxuan Weng, School of New Materials and Future Technologies, Beijing Technology and Business University, No.11 Fucheng Road, Haidian District, Beijing 100048, China
Xiaoying Zhao, School of New Materials and Future Technologies, Beijing Technology and Business University, No.11 Fucheng Road, Haidian District, Beijing 100048, ChinaFollow

Keywords

Aflatoxin B1; Colorimetric detection; DNA-crosslinked hydrogel；Mycotoxin detection；Signal amplification

Abstract

Aflatoxin B1 (AFB1) poses a severe threat to food safety due to its potent carcinogenicity. To address the need for rapid and on-site detection, this study developed a colorimetric biosensor based on an AFB1-responsive DNA aptamer-cross-linked sodium alginate hydrogel. Gold nanoparticles (AuNPs) were encapsulated within the hydrogel as a visual signal reporter. The sensing mechanism relies on target-induced dissociation of aptamer crosslinkers, leading to hydrogel disintegration and release of AuNPs. The hydrogel formulation was optimized regarding sodium alginate concentration and crosslinking conditions. To enhance sensitivity, an Exonuclease I (Exo I)-triggered target recycling strategy was implemented, which amplifies hydrogel network disruption by cleaving and recycling the aptamer. The sensor demonstrated a linear detection range of 0-50 µM, with a detection limit of 12.9 nM, and exhibited high selectivity towards AFB1. This work presents a sensitive, visually readable, and portable platform for mycotoxin detection in food safety applications.

Recommended Citation

Du, Haojie; Liu, Haoyue; Li, Yongshuai; Wei, Shiyi; Wang, Xinning; Weng, Yunxuan; and Zhao, Xiaoying (2026) "A target-responsive and signal-amplified DNA hydrogel biosensor for visual and quantitative detection of Aflatoxin B1," Journal of Food and Drug Analysis: Vol. 34 : Iss. 3 , Article 15.
Available at: https://doi.org/10.38212/2224-6614.3608