A highly sensitive and selective one-dimensional Ag@hydrogen-bonded organic framework-based biosensor for the detection of the prohibited food additive ractopamine

In this study, a novel and highly responsive biosensor was engineered for the identification of ractopamine (RAC), an illicit additive used to stimulate muscle development in farm animals. A hydrogen-bonded organic framework (HOF) was synthesized via a simple, economical, and environmentally friendly approach. To reinforce the electrochemical performance, silver nanoparticles (Ag NPs) were integrated into the HOF, thereby enlarging the electrode's active surface area and facilitating greater immobilization of RAC-specific aptamers (Apt). The successful immobilization of Apt RAC on the Ag@HOF-coated glassy carbon electrode (GCE) was validated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). This sensing platform displayed a wide linear detection range from 0.01 fM - 0.25 nM, with an outstanding detection limit of 4 aM. Furthermore, the sensor demonstrated excellent specificity against potential interfering agents. Its reliable performance was also confirmed in complex biological samples, including milk and meat, indicating strong potential for practical, real-world applications.