Mesoporous hematite nanoparticles (HNPs) encapsulated SiO₂–TiO₂ nanocomposites (STNC) are synthesized and heat-treated at low-temperature 50 °C for 1h (STNC/1h) and 2h (STNC/2h) by sol-gel process for hydrocarbons chemical sensing. Microscopic analysis revealed the thermally stable hierarchical structure of HNPs, which changed into aggregated porous spherical morphology after encapsulation in STNC and heat treatment. The low surface area of HNPs ~55 m²/g which is increased up to 289 m²/g for H-STNC/2h, is advantageous to enhance sensing device activity. Magnetic properties exhibited the superparamagnetic behavior of H-STNC/2h. The H-STNC/2h coated fiber optic chemical sensor revealed a linear response towards the higher carbon chains, sensitivity is calculated as 5.3 counts per unit variations in the carbon chain at 515 nm with R² ~ 0.98. The proposed magnetic sensing device has good reversibility, stability, and validity without any leaching traces.

合成介孔赤铁矿纳米粒子 (HNPs) 封装的 SiO ₂ –TiO ₂纳米复合材料 (STNC)，并通过溶胶-凝胶工艺在 50 °C 的低温下热处理 1 小时 (STNC/1h) 和 2 小时 (STNC/2h) 烃化学传感。显微分析揭示了 HNPs 的热稳定分级结构，在 STNC 封装和热处理后转变为聚集的多孔球形形态。HNPs 的低表面积 ~55 m ² /g，增加到 289 m ²/g 表示 H-STNC/2h，有利于增强传感设备的活动。磁性表现出 H-STNC/2h 的超顺磁行为。H-STNC/2h 涂层光纤化学传感器显示出对较高碳链的线性响应，灵敏度计算为 515 nm 处碳链中每单位变化 5.3 个计数，R ² ~ 0.98。所提出的磁传感装置具有良好的可逆性、稳定性和有效性，没有任何浸出痕迹。