Smartphone-assisted fluorescence sensor based on iron-doped carbon dots for rapid detection of tert-butyl hydroquinone in edible oils

Fe 3+ -regulated on-off-on probe was constructed for TBHQ detection in edible oils. • The probe shows low LOD (0.0067 μM) with good stability (−40 to 100 °C, pH 1–11). • Recovery rates in soybean oil range 98.60%–100.40% (RSD <2.1%). • Smartphone-assisted RGB analysis enables on-site TBHQ quantification via G/R ratio. Given the health risks of tert-butylhydroquinone (TBHQ), rapid, portable, selective, and sensitive quantification in edible oils is critical. With this in mind, a fluorescent “on–off–on” probe was developed based on rationally designed iron-doped carbon dots (CDs). The blue fluorescence of the CDs is quenched by Fe 3+ ions and recovered by TBHQ, enabling Fe 3+ detection in an “on–off” mode and TBHQ detection in an “off–on” mode. The probe exhibited excellent linearity for TBHQ over the range of 0.2–1.8 μM, with a low detection limit of 0.067 μM. Moreover, a smartphone-assisted sensor was constructed to enable portable TBHQ quantification in edible oils samples. This CD-based probe shows strong promise for the rapid, sensitive, and cost-effective monitoring of hazardous substances. Download: Download high-res image (93KB) Download: Download full-size image