Electrochemiluminescence and Fluorescence Dual-Mode Monitoring of Aflatoxin B1 Production Based on Single Ru-Mof Particles and Fitc Luminophores

Abstract

Herein, an electrochemiluminescence (ECL) and fluorescence (FL) dual-mode imaging biosensing platform was developed for onsite and dynamic monitoring of aflatoxin B1 (AFB1) production in the corn molding process. Zinc metal organic framework structures encapsulated with Ru(bpy)32+ (Ru-MOF) were employed as ECL signal probes for single particle imaging with stable luminescent intensity and high emission efficiency. FITC luminophores, served as fluorescent probes, were conjugated with AFB1 aptamer modified on the electrode surface, which enabled the observation of green luminescent spots in FL mode. When exposed to target AFB1, FITC luminophores detached from the surface of electrode, leading to a notable decrease in the number of green luminescent spots. Single Ru-MOF particles were then immobilized onto the surface of electrode through DNA coupling and discernible luminescent spots could be watched in ECL mode. The results showed that aflatoxin production occurred more rapidly at damaged areas of the corn compared to areas with intact surfaces. The intact corn got moldy on the third day and its surface AFB1 concentration was calculated as 14.16 fg/mL. This work achieves satisfactory performances for AFB1 monitoring which provides innovative ideas for the rational design of aflatoxin sensors, and holds substantial promise in food safety.

Keywords: Dual-mode imaging, Fluorescence, electrochemiluminescence, aflatoxin, onsite monitoring