FeNi Prussian blue analogues on highly graphitized carbon nanosheets as efficient glucose sensors

Meeting the continuous glucose monitoring requirements of individuals necessitates the research and development of sensors with high sensitivity and stability. In this study, a straightforward strategy was proposed for synthesizing ultra-thin oxygen-rich graphitized carbon nanosheets (denoted as GCS-O). These nanosheets are obtained by calcining a topologically two-dimensional indium-based coordination polymer. Subsequently, the growth of FeNi Prussian blue analogue (PBA) on GCS-O effectively introduces active sites and increases the nitrogen content within the carbonaceous matrix. The resulting FeNi-PBA/GCS-O composite exhibits excellent glucose sensing performance with a broad linear range of 1 to 1300 μmol·L⁻¹. Meanwhile, it also achieves a high sensitivity of 2496 μA·mmol⁻¹·L·cm⁻², a limit of detection of 100 nmol·L⁻¹ (S/N = 3), and commendable long-term durability. The relatively simple synthesis process, exceptional sensitivity, and satisfactory electrochemical sensing performance of FeNi-PBA/GCS-O open up new directions for biosensor applications.