Development of Molecularly Imprinted Polymer Electrochemical Sensors for Strawberry Sweetness Biomarker Detection
ACS Applied Polymer Materials 6, 8084 (2024)
This study introduces an approach utilizing a molecularly imprinted electrochemical sensor for monitoring the condition of naturally ripened strawberries. Furaneol, known as 2,5-dimethyl-4-hydroxy-3(2H)-furanone, serves as a crucial biomarker associated with strawberry flavor. However, accurately detecting furaneol concentration has posed a challenge due to its nonpolar, unreactive nature, and decomposition using high-performance liquid chromatography and gas chromatography coupled with mass spectrometry, leading to inaccuracies in detection methods. To address this issue, we developed a furaneol-imprinted molecularly imprinted polymer (MIP)-based electrochemical sensor. Our findings demonstrate the specific binding site formation using copolymerization of poly(methacrylic acid) (PMAA) as a sensing material and polyaniline (PANI) as the redox-active matrix to achieve sensitive and selective detection of furaneol using the furaneol-imprinted PANI (Fur-PANI) sensor. A comparison between MIP and nonimprinted polymer-based sensors highlights a robust interaction between furaneol and the MIP, showing an enhanced detection signal of more than twice. We elucidate the mechanism for electrochemical detection of protonated furaneol molecules based on charge carrier transfer through the oxidation mechanism of PANI-based sensors corresponding to the change of current density. Additionally, we investigate the long-term stability of the Fur-PANI sensor over a month, highlighting its potential to serve as a cost-effective, rapid, and durable sensor platform for specific furaneol recognition.