High‐Throughput Glucose Biosensing Using Jack Bean [ <i>Canavalia ensiformis</i> (L.) DC.] Lectin as Electrochemical Signaling Element

Lectins are widely recognized for their ability to selectively bind carbohydrates, making them valuable proteins in biosensor design. In this work, we developed a label‐free electrochemical platform using jack bean [ Canavalia ensiformis (L.) DC.] lectin (ConA) immobilized on a Prussian Blue‐modified electrode to detect glucose from submicromolar levels. While ConA presents both electron‐rich and electron‐deficient regions due to the variety of functional groups along its peptide chain (e.g., COOH, OH, SH, in addition to Ca 2+ and Mn 2+ coordinated sites), Prussian Blue was selected for its biocompatibility, chemical stability, semiconducting behavior, and peroxidase‐mimicking activity, which enhanced signal amplification (3.94 × 10 3 µA µmol L −1 cm −2 ) without compromising the lectin's biorecognition functionality. Using square‐wave voltammetry (25 Hz frequency, 40 mV amplitude, and 0.5 mV potential increment), the biosensor achieved a detection limit of 0.56 µmol L −1 glucose, with excellent precision (RSD ≤ 7.5% in intraday and interday tests) and high accuracy (RSD = 7.8% across different devices). The biosensor was successfully tested in glucose‐enriched commercial formulations (98.0% –103.5% recovery), demonstrating high electroanalytical performance despite the presence of potentially interfering additives such as dyes, antioxidants, mineral salts, and other carbohydrates. These findings highlight the potential of ConA‐based biosensors as simple and reliable platforms for analyzing free and conjugated glucose in complex samples.