Self-powered electrochemical glucose sensing enabled by zirconium holmium oxide/MXene/graphene nanocomposites with integrated energy storage

초록

Advanced wearable electronics and self-powered diagnostic devices require electrode materials that can combine efficient energy storage with reliable biosensing. This study reports a multifunctional zirconium holmium oxide/titanium carbide MXene/graphene composite, denoted as ZrHo2O4/Ti3C2Tx MXene/graphene, synthesized by a hydrothermal method and evaluated as an electrode for hybrid supercapacitor performance and non-enzymatic glucose detection. Structural, surface, and morphological analyses confirmed the integration of crystalline ZrHo2O4 with conductive Ti3C2Tx-MXene and graphene, producing a porous and interconnected architecture favorable for charge transport and electrochemical activity. The ZrHo2O4/Ti3C2Tx MXene/graphene electrode demonstrated a specific capacity (Qs) of 315.22 C g-1. When assembled with activated carbon as a battery-type hybrid supercapacitor, the device achieved a Qs of 315.22 C g-1, an energy density of 35.94 Wh kg-1, and a power density of 1275 W kg-1, while retaining 88% of its capacity after 5000 cycles. For glucose sensing in phosphate-buffered saline, the modified electrode exhibited a linear response from 0.1 mu M to 1.6 mM, a sensitivity of 5.1 mu A mM-1 cm-2, and a detection limit of 0.03 mu M. It also revealed a 15 s response time, selectivity against common interfering species, reproducibility, and signal stability. These results demonstrate that ZrHo2O4/Ti3C2Tx-MXene/graphene is a promising dual-function electrode for integrated energy-storage and glucose-sensing platforms in wearable and point-of-care devices.

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