A Si‐CdTe Composite Quantum Dots Probe with Dual‐Wavelength Emission for Sensitively Monitoring Intracellular H₂O₂

Abstract

Hydrogen peroxide is an important reactive oxygen species (ROS) that acts as a significant marker of oxidative stress in certain diseases. Owing to the autofluorescence of biological samples, H 2 O 2 monitoring remains challenging. Here, Si-CdTe quantum dots (QDs) are prepared as novel ratiometric fluorescent probes prepared for sensitive detection of H 2 O 2 and glucose, the low detection limit of H 2 O 2 and glucose is 79 and 140 nm, respectively. In this article, CdTe QDs are combined with Si QDs to reduce the cytotoxicity of CdTe. The survival rate of HeLa cells remains at 80% after incubation with the Si-CdTe QDs at a concentration of 500 µg mL −1 for 24 h. Fluorescence extinguishes based on 488 and 514 nm channels are used as internal references to avoid environmental interference and demonstrate selective H 2 O 2 biosensing. In addition, the probe has an excellent colocalization effect in the lysosome under the 514 nm channel, with a maximum Pearson coefficient of 0.96. The advantages of easy preparation, low toxicity, high resistance to photobleaching, and high specificity of the Si-CdTe QDs probes provide a new and convenient means to monitor and detect changes in the endogenous intracellular H 2 O 2 concentration and to select 514 nm lysosomal colocalization dyes.

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

“…The 1390 cm –1 peak originates from the bending vibration of the O–H bond of the carboxylic acid. These results indicate that the CQDs and CdTeQDs are mutually adsorbed. , …”

“…These results indicate that the CQDs and CdTeQDs are mutually adsorbed. 38,39 The elements and chemical components of C-CdTeQDs are revealed by X-ray photoelectron spectroscopy (XPS). As shown in Figure 1f, C The strong signal of the C−C coordination is ascribed to the predominantly carbonized character of this material.…”

“…The water-soluble TGA-capped CdTe QDs were synthesized following a reflow procedure . 0.25 mmol CdCl 2 , 0.3 mmol TGA, and 0.54 mmol sodium citrate were added sequentially to a 25 mL three-necked flask.…”

Recent Updates on Functionalized Silicon Quantum-Dot-Based Nanoagents for Biomedical Applications

“…151,152 In 2022, Zhou et al developed a FRET-based ratiometric nanoprobe, a composite of Si QDs and CdTe QDs (Si-CdTe QDs), for sensitive determination of H 2 O 2 and glucose with a low LOD of 79 and 140 nM, respectively. 136 This nanoprobe possesses a strong fluorescence at 562 nm and a weak fluorescence at 442 nm under UV irradiation, where FRET occurs between Si QDs and CdTe QDs (Figure 9a). When this nanoprobe meets with H 2 O 2 , the thioglycolic acid on CdTe QDs is disassociated, thus resulting in the emission at 562 nm disappearing and that at 442 nm becoming intense (Figure 9b).…”

“…In recent years, Si QD-based sensing probes have been widely developed and applied to the detection of many biological/environmental analytes. Many efforts have been devoted to improving sensor performance, achieving higher sensitivity and reliability, shorter response time, and lower detection limits. − The rational design of Si QD-based sensing platform opens new opportunities for the quantification of analytes and disease-related biomarkers, paving the way for clinical applications of disease diagnosis and treatment.…”