Abstract
Electrical impedance spectroscopy (EIS), referred to as bioimpedance when used to characterize biological tissues, is emerging as a powerful, low-cost, and non-invasive technique for real-time assessment of fruit quality. It enables detection of physiological, biochemical, and structural changes during ripening, as well as internal defects, microbial contamination, and postharvest stress during storage and transport. Nevertheless, achieving accurate and reliable fruit bioimpedance measurements requires careful consideration of electrode design, flexibility, and stability of the electrode–fruit interface. This perspective traces the technological evolution of electrodes for fruit sensing, highlighting the transition from conventional ECG-inspired platforms to soft, unconventional architectures and bio-based sustainable solutions, including cellulose substrates, epidermal-mimetic electrodes, corn-protein conductive adhesives, and other biosourced materials. Recent fabrication strategies exploiting natural substrates, carbon-based composites, and agro-waste materials to improve conductivity, conformability, and environmental compatibility are examined. Emerging biocompatible, biodegradable, and circular electrode architectures are highlighted as promising pathways to reduce ecological footprint and electronic waste while maintaining signal fidelity. Key challenges including conductivity variability, instability at the electrode–substrate interface, and limited reproducibility across heterogeneous biological matrices are assessed. Finally, a roadmap is outlined for integrating sustainable materials with scalable manufacturing routes toward next-generation EIS platforms for precision agriculture and horticultural sensing.