3D printed bionic self-powered sensing device based on fern-shaped nitrogen doped BiVO photoanode with enriched oxygen vacancies.

A portable three-dimensional (3D) printed bionic sensing device with enhanced photoelectric response was fabricated for sensitive detection of Bisphenol A (BPA). The proposed sensor is operated upon by using a highly reactive dual-electrode system to generate electrical output and provide the sensing signal under photoirradiation, without an external power source. The fern-shaped nitrogen doped BiVO photoanode with enriched oxygen vacancies (O) bismuth vanadate (N/O/BiVO) photoanode was first synthesized and applied to construct a bionic sensing device. Density functional theoretical (DFT) calculation shows that the synergistic of nitrogen doping and O on the surface of photoanode leads to the emergence of impurity levels in BiVO's electronic structure, promoting the effective separation of photogenerated electron-hole pairs. Impressively, the unique fern-shaped bionic structure enhances the mass transfer efficiency of the sensing system and provides abundant binding sites of aptamer, realizing signal amplification. Moreover, a portable sensing device for automatic sample injection and detection is developed by integrating the detection system into a micromodel based on micro-nano 3D printing technology. Benefit from this ingenious design, the proposed bionic aptasensor displayed excellent electricity output and achieved high sensitivity and selectivity of BPA detection with a low limit of detection (0.025 nM) and broad linear range from 0.1 nM to 100 μM, paving a new way for the development of portable and on-site sensing devices.