Laser-Scribed Graphene Electrodes Derived from Lignin for Biochemical Sensing
Laser scribing of porous graphene electrodes on flexible substrates is of great interest for developing disposable electrochemical biosensors. In this work, we present a new patterning process for highly conductive nitrogen-doped graphene derived from a lignin-based precursor. A CO2 laser scribing process was performed under ambient conditions to produce the porous graphene electrodes from lignin. The obtained nitrogendoped laser-scribed graphene (N-LSG) is binder-free, hierarchical, and
... rchical, and conductive. The interconnected carbon network displayed enhanced electrochemical activity with improved heterogeneous electron transfer rate. These features can be attributed to the highconductivity of porous N-LSG (down to 2.8 Ω per square) and its enriched active edge plane sites. Furthermore, the N-LSG electrodes were decorated with MXene/Prussian Blue (Ti3C2Tx/PB) composite via a simple spray coating process, designed for sensitive 2 detection of analytes. The Ti3C2Tx/PB modified N-LSG electrodes were functionalized with catalytic enzymes for detecting glucose, lactate, and alcohol. The enzyme/Ti3C2Tx/PB/N-LSG electrodes exhibited remarkably enhanced electrochemical activity toward the detection of these biomarkers, making them highly competitive with previously reported on-chip carbon-based biosensors. Therefore, our sensors demonstrate excellent potential for applications in personalized healthcare.