Heterogeneous CuO 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 CuO (h-CuO) 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-CuO nano-skeletons, with an inner core predominantly composed of CuO with lower oxygen content, juxtaposed with an outer layer rich in amorphous CuO (a-CuO) with higher oxygen content, are derived from discarded printed circuit boards. When employed in glucose detection, the h-CuO nano-skeletons undergo a structural evolution process, transitioning into rigid CuO@CuO nano-skeletons prompted by electrochemical activation. This transformation yields exceptional glucose-sensing performance (sensitivity: 9.893 mA mM cm; 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.