Microplasma synthesis of magnetic carbon hybrids as new colorimetric sensor probes for detecting and quantifying of...

In this study, a novel hybrid composed of carbon dot (CD)-decorated magnetic nanoparticles (Fe₃O₄@CD) was synthesized using a microplasma process and demonstrated as a new colorimetric sensing probe for peroxide-based detection and quantification of phenolic compounds in water. The ability to detect and quantify four phenolic compounds-phenol, m-cresol, guaiacol, and syringol-was confirmed. Among the tested compounds, phenol exhibited the highest sensitivity, with a limit of detection (LOD) of 0.030 ± 0.0015 μM and a quantitative analytical range of 0.025-1.00 μM. The Fe₃O₄@CD sensing probe also effectively detected and quantified m-cresol in the range of 0.1-1 μM, and guaiacol and syringol in the range of 1-10 μM. Interestingly, p-cresol and 4-nitrophenol showed minimal reactivity, allowing for their selective differentiation from other phenolic compounds. The underlying mechanism of the colorimetric reaction was elucidated, highlighting the sensitivity, specificity, and superior performance compared to other colorimetric methods. This innovative Fe₃O₄@CD hybrid colorimetric sensing probe offers a promising, low-cost solution for the efficient detection and quantification of phenolic pollutants, with potential applications in environmental monitoring and public health safety.