C-CdTe Quantum Dots as Dual-Wavelength Fluorescence and Colorimetric Probes to Detect Hydrogen Peroxide, Hydroxyl Radicals, and Iron(II) in Serum

The Fenton reaction has been widely utilized in tumor therapy and ferroptosis immunity in recent years. Therefore, the detection of hydrogen peroxide (H2O2), hydroxyl radicals (•OH), and iron(II) (Fe2+) in serum is urgently in need. A multifunctional combined carbon–CdTe quantum dots (C-CdTeQDs) probe is first established for the quick succession determination of H2O2 and Fe2+ in goat serum and human urine based on the fluorescence and colorimetric method. The double-emission fluorescence detection is performed by breaking the thioglycolic acid bond on the surface of CdTeQDs by H2O2 to quench the fluorescence at 594 nm. After the condition optimization, the fluorescence intensity is linearly related to H2O2 concentration, with a limit of detection of 58 nM. The colorimetric detection of •OH and Fe2+ concentrations is then continued by the Fenton reaction and the complexation reaction. Among them, the detection range of •OH is 0.01–0.1 μM with the limit of detection of 8 nM. Several advantages such as versatility, convenience, high selectivity, and sensitivity of the C-CdTeQDs probe indicated that it has great potential for the determination of H2O2 and Fe2+ in serum.