rGO-K-CD-MOFs based non-enzymatic electrochemical sensor toward sensitive hyodeoxycholic acid determination

The increasing utilization of hyodeoxycholic acid (HDCA) additives in animal feed has created a pressing need for reliable detection methods. This study presents a novel non-enzymatic electrochemical platform for specific detection of HDCA using liquid nanocomposites from potassium-coordinated cyclodextrin metal-organic frameworks (K-CD-MOFs) immobilized on reduced graphene oxide (rGO) substrates. Employing neutral red (NR) as the probe, rGO-K-CD-MOFs@NR exhibits outstanding sensing performance with a wide linear detection range (5.0–100.0 μM), a high sensitivity (0.10 μA·μM⁻¹), and low detection limit (1.97 μM, S/N = 3). The sensor also demonstrates exceptional selectivity for HDCA and maintains stable performance for six months under low-temperature storage conditions. The excellent performance originates from the synergistic effect between rGO's excellent electron transfer capability and K-CD-MOFs' unique host-guest recognition properties. This work not only provides an effective solution for HDCA monitoring in feed products but also offers a promising strategy for developing advanced electrochemical sensors for food safety and quality control applications in the animal husbandry industry.