Enhanced fluorescent iron oxide quantum dots for rapid and interference free recognizing lysine in dairy products

Polyvinylpyrrolidone-passivated fluorescent Iron oxide quantum dots for turn-off detection of tetracycline in biological fluids

“…The fluorescence intensity increases when the IO NPs at concentration of 0.1 mg/mL to 0.5 mg/mL and declines when the concentration of IO NPs is 1.0 mg/mL. The amount of PVP of 0.25 g results in the highest fluorescence intensity compared to the other amount of PVP at 0.05 g and 0.1 g. The crystal growth process of the IO QDs formation was found to be influenced by the precursor concentration of IO NPs and PVP result in the best fluorescence properties [ 30 ]. The reaction time and temperature are also important to gain the optimized fluorescence features.…”

“…Iron oxide QDs (IO QDs) were successfully synthesized in 2019 and were applied in catalysis reactions [ 29 ]. Since then, researchers have expressed high interest in exploring the potential of IO QDs for other activities or sensing applications [ 29 , 30 ]. IOQDs constitute a new series of nanomaterials with FL properties.…”

Amorphous Ultra‐Small Fe‐Based Nanocluster Engineered and ICG Loaded Organo‐Mesoporous Silica for GSH Depletion and Photothermal‐Chemodynamic Synergistic Therapy

“…According to previous reports, Fe 3+ from Fe(NO 3 ) 2 • xH 2 O could be converted to FeOOH under weak alkali condition, and then the as prepared FeOOH transformed into the crystalline Fe 3 O 4 quantum dots after calcination at 400 °C for 2 h. [ 15 ] The reported Fe based quantum dots exhibit various luminescence peaks from 395 to 480 nm when the excitation wavelength was changed from 280 to 420 nm. [ 16 ] Accordingly, in order to realize a more intuitive observation of Fe‐based nanogranules released from omSN@Fe under GSH triggering, Fe‐based nanogranules were pre‐calcined in an Ar atmosphere at 400 °C for 2 h and then the obtained Fe‐based quantum dots with size of ≈7.7 nm presented strong fluorescence at 475 nm under 400 nm ligh excitation (Figure 2B; Figure S6, Supporting Information). Importantly, in vitro fluorescence intensity of the Fe‐based quantum dots was dramatically increased in the presence of 10 m m GSH (Figure 2B).…”

“…• xH 2 O could be converted to FeOOH under weak alkali condition, and then the as prepared FeOOH transformed into the crystalline Fe 3 O 4 quantum dots after calcination at 400 °C for 2 h. [15] The reported Fe based quantum dots exhibit various luminescence peaks from 395 to 480 nm when the excitation wavelength was changed from 280 to 420 nm. [16] Accordingly, in order to realize a more intuitive observation of Fe-based nanogranules released from omSN@Fe under GSH triggering, Fe-based nanogranules E) omSN@Fe-ICG. Magnified TEM images of F) omSN, G) Fe-based nanogranules, and H) omSN@Fe-ICG.…”

Turn-off/turn-on biosensing of tetracycline and ciprofloxacin antibiotics using fluorescent iron oxide quantum dots

“…Fe 3 O 4 NPs (0.01 mg mL −1 , 5 mL) and l -cysteine (0.01 g) were mixed and sonicated for 10 min, where the Fe 3 O 4 NPs were synthesized as previously described. 27 This solution was then placed in a hydrothermal Teflon vessel and kept at 200 °C for 12 h for a hydrothermal reaction. The resulting solution was first filtered using a 0.22 μm membrane filter and stored in a refrigerator at 4 °C for further experiments.…”