Electrochemical detection of xylobiose in banana biomass using a 3D porous copper oxide foam electrode modified with a molecularly imprinted Poly-L-arginine film

Xylobiose (X2) presents numerous health benefits, including cancer prevention, and can be found in agro-industrial biomass, including bananas. Here, an electrochemical sensor based on molecularly imprinted poly-L-arginine film (MIP) and 3D porous copper oxide foam (3DnpCu) for the ultrasensitive detection of X2 is studied. The MIP/3DnpCu-GCE is prepared by dynamic hydrogen bubble template method, followed by electropolymerization of L-arginine in the presence of X2 as template, followed by electrochemical extraction, resulting in the formation of X2 recognition sites. The sensor was characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. MIP/3DnpCu-GCE showed a wide linear response in the concentration range of 1.0 × 10−12 to 1.0 × 10−10 mol L−1, limit of detection of 7.7 × 10−13 mol L−1 and sensibility of 1.4 µA pmol−1 L. The sensor exhibited selective X2 recognition, long-term stability (maintaining 86% of its initial current over 8 days), while inter-electrode repeatability displayed an RSD of 2.4%. The applicability of the MIP/3DnpCu-GCE in real samples is demonstrated by successfully quantifying X2 concentration in banana biomass. Furthermore, the comparison between the data obtained using this method and those found by the HPLC method confirmed the accuracy of the sensor.