High-Performance Sensor Based on Molecularly Imprinted Poly-o-Phenylenediamine for Determination of Pentoses in Hydrolyzates of Lignocellulosic Biomass

Molecularly imprinted polymer (MIP) sensors were developed to determine d-xylose and d-arabinose in hydrolyzates of lignocellulosic biomass from sugarcane. Sensors were fabricated using molecularly imprinted poly-o-phenylenediamine anchored on composite substrates of functionalized multiwalled carbon nanotubes (FMWCNTs) electrodeposited onto a graphite/paraffin surface. The characterization of the modified electrodes and electrochemical analyses involved the utilization of spectroscopy and electroanalytical techniques such as Fourier-Transform Infrared Spectroscopy (FT-IR), Field Emission Gun Scanning Electron Microscopy (FEG-SEM), Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), and Differential Pulse Voltammetry (DPV). These techniques were employed to gain insight into the modified electrodes' properties and behavior and perform detailed electrochemical analyses. In addition, the most critical parameters that directly affect the analytical performance of the electrochemical sensor have been optimized. The sensors showed a limit of detection (LOD) of 6.1 × 10^-12 mol L^-1 for d-xylose and 2.5 × 10^-12 mol L^-1 for d-arabinose, in the linear range of concentration from 1.0 × 10^-11 mol L^-1 to 1.0 × 10^-10 mol L^-1. The employed sensor effectively facilitated the quantification of d-xylose and d-arabinose within hydrolyzate samples derived from sugarcane bagasse.