Boron-doped carbon nanowalls as effective electrodes for non-enzymatic electrochemical glucose detection: A novel bimodal EC-SALDI-MS approach

For the first time, boron-doped carbon nanowalls (B-CNWs) have been used as effective working electrodes for non-enzymatic electrochemical glucose detection. To achieve optimal response time and sensitivity, we activated B-CNWs by polarising them at 1.1 V in NaOH for 60 min. We established a robust linear dynamic range for glucose concentrations from 10 to 550 μM and calculated a limit of detection (LoD) of 10 μM. Additionally, B-CNWs demonstrated excellent selectivity for glucose, even in the presence of various interfering compounds like its isomer, galactose. Importantly, we showed that B-CNWs could detect gluconic acid, the oxidation product of glucose, using mass spectrometry in an off-line configuration. This novel approach combines electrochemical (EC) and surface-assisted laser desorption/ionisation mass spectrometry (SALDI-MS) detection, utilising the same nanomaterial (B-CNWs) in a bimodal configuration. This coupling represents a significant advancement in glucose sensing technology by leveraging the unique properties of B-CNWs and providing a powerful analytical tool for detecting, identifying, and understanding a wide range of chemical compounds and processes.