Ultrasensitive electrochemical chloramphenicol sensor using laser-induced polyoxometalate-based metal-organic compound and polyimide derived nanocomposite

Chloramphenicol (CAP) is a broad-spectrum antibiotic whose overuse poses environmental and public health risks, making rapid detection crucial. This study introduced a nanocomposite of CeO 2 , SiO 2 , and MoC nanoparticles in situ embedded in laser-induced graphene (CeO 2 -SiO 2 -MoC-LIG). The nanocomposite was synthesized via a laser-induced method using a polyoxometalate-based metal-organic compound and a polyimide mixture, and was further characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and Brunauer-Emmett-Teller analysis. The incorporation of nanoparticles significantly improved the conductivity, electrochemical response, specific surface area, and the number of active sites at the LIG electrode interface. Under optimal conditions, the CeO 2 -SiO 2 -MoC-LIG electrode enabled detection of CAP via linear sweep voltammetry, achieving a wide detection range of 0.1 μM–1.0 mM and a low limit of detection of 33 nM. The electrode also exhibited excellent selectivity against common antibiotics (peak current changes <12.1% at five-fold concentrations of interferents) and good stability (retaining 95.6% of the initial response after 9 days). Furthermore, this flexible electrode was successfully applied to monitor CAP in tap water and pork samples with satisfactory recoveries (96.3%–102.8%) and relative standard deviations below 3.34%, presenting a novel approach to designing flexible electrochemical devices.