Heterogeneous Cu_xO Nano-Skeletons from Waste Electronics for Enhanced Glucose Detection

Electronic waste (e-waste) and diabetes are global challenges to modern societies. However, solving these two challenges together has been challenging until now. Herein, we propose a laser-induced transfer method to fabricate portable glucose sensors by recycling copper from e-waste. We bring up a laser-induced full-automatic fabrication method for synthesizing continuous heterogeneous Cu_xO (h-Cu_xO) nano-skeletons electrode for glucose sensing, offering rapid (< 1 min), clean, air-compatible, and continuous fabrication, applicable to a wide range of Cu-containing substrates. Leveraging this approach, h-Cu_xO nano-skeletons, with an inner core predominantly composed of Cu₂O with lower oxygen content, juxtaposed with an outer layer rich in amorphous Cu_xO (a-Cu_xO) with higher oxygen content, are derived from discarded printed circuit boards. When employed in glucose detection, the h-Cu_xO nano-skeletons undergo a structural evolution process, transitioning into rigid Cu₂O@CuO nano-skeletons prompted by electrochemical activation. This transformation yields exceptional glucose-sensing performance (sensitivity: 9.893 mA mM^-1 cm^-2; detection limit: 0.34 μM), outperforming most previously reported glucose sensors. Density functional theory analysis elucidates that the heterogeneous structure facilitates gluconolactone desorption. This glucose detection device has also been downsized to optimize its scalability and portability for convenient integration into people's everyday lives.