A portable gold microneedle electrochemical sensor for real-time detection of p-benzoquinone in electrolysis process

A real-time p-benzoquinone (PBQ) sensor with simplified fabrication was developed and integrated with organic electrosynthesis for in situ detection during electrochemical production. The portable microneedle sensor was constructed using a self-supporting nanoporous gold wire substrate, fabricated through a two-step process: anodization under fluoride ion modulation, and followed by chemical reducing in a mixed solution of ascorbic acid and SnCl₂. The introduction of fluoride ions during the anodization significantly enhanced the electrochemical detection performance (83 % PBQ reduction property improvement), attributed to their strong coordination capability in pore structure engineering. The sensor's detection range (5.56 μM-1.53 mM) was designed to encompass both initial and terminal PBQ concentrations in typical production processes. Comparative validation with HPLC demonstrated a measurement accuracy of ±3.9 %, maintaining precision in both blank matrices and complex reaction mixtures containing additives. Key performance metrics included 1.0 second response time and sustained operational stability over 7 continuous days (<5 % signal attenuation). The device exhibited exceptional selectivity against common coexisting species: phenol (99 % recovery), resorcinol (92.8 %), catechol (CT, 94.8 %), hydroquinone (HQ, 98.9 %), maleic acid (MH, 91.6 %), and oxalic acid (OA, 90.4 %). This methodology establishes a prototype for adaptive chemical monitoring platforms, demonstrating significant potential for real-time process analytics in diverse electrochemical synthesis applications.