Photoelectrochemical biosensing for non‐enzymatic carbamazepine detection: Tailoring <scp>MWCNTs</scp> for enhanced sensitivity

Abstract This study introduces a novel photoelectrochemical (PEC) biosensor for the detection of carbamazepine (CBZ), emphasizing the crucial role of precisely engineered multiwalled carbon nanotubes (MWCNTs). We transformed MWCNTs into short‐cut MWCNTs (SC‐MWCNTs) and graphene nanoribbons (GONRs) through controlled microwave and acid treatments and investigated the impact of these modifications on their electrochemical effective area (EA) and sensing performance. Transmission electron microscopy (TEM) was employed to characterize the resulting morphology and microstructure. Cyclic voltammetry (CV) measurements were conducted to assess the faradaic current response and quantify the EA of the synthesized materials. A strong correlation was observed between the EA and the CBZ sensing capabilities of the modified MWCNTs. Notably, the SC‐MWCNT electrode treated for 2 h exhibited a remarkable 123% enhancement in PEC faradaic current compared with its electrochemical counterpart, demonstrating exceptional potential for highly sensitive PEC‐based CBZ detection. This research highlights the significance of controlled modification of MWCNTs to optimize their EA for efficient and reliable CBZ monitoring, paving the way for advancements in carbon‐based nanomaterial applications in PEC biosensor development and potentially reducing the reliance on extensive analyte testing during optimization.