High-sensitivity biogenic amine detection via engineered binder formulation in resonant microcantilever gas sensors: A case study of cadaverine

Abstract

Electronic nose (e-nose) technologies rely on functional layers to enable selective detection of target analytes. While previous work has focused on improving repeatability through surface treatments and binder placement, challenges in sensitivity have limited the detection of early-stage spoilage in food applications. In this study, we present an approach to enhance the sensitivity of a piezoelectrically driven microcantilever (PD-MC) based e-nose by engineering the sensing material (binder) composition for cadaverine, while optimizing the sensing mechanism and improving surface application capabilities. Cadaverine is a proven biogenic amine associated with the spoilage of meat. The sensing material is synthesized by complexing Nickel with Cyclam in barium hydroxide, forming a square planar [Ni(cyclam)]²⁺ complex, and modified cyclam with substituted moieties, which forms a viscous glue used as a buffer for the active components and aiding in immobilization on the PD-MC surface. The modified binder formulation is found to enable the detection of cadaverine concentrations as low as 30 μg/kg, allowing for the differentiation between meat freshness on day 1 and day 2. This is a significant improvement over the previously reported detection threshold. Enhanced sensitivity is achieved without compromising repeatability or selectivity, as demonstrated through controlled exposure experiments and resonance frequency analyses. These findings largely advance the development of high-sensitivity, scalable e-nose systems for real-time monitoring of food freshness.