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Engineering iodine-doped carbon dots as dual-modal probes for fluorescence and X-ray CT imaging.

Zhang M, Ju H, Zhang L, Sun M, Zhou Z, Dai Z, Zhang L, Gong A, Wu C, Du F - Int J Nanomedicine (2015)

Bottom Line: Importantly, I-doped CDs displayed superior X-ray attenuation properties in vitro and excellent biocompatibility.After intravenous injection, I-doped CDs were distributed throughout the body and excreted by renal clearance.These findings validated that I-doped CDs with high X-ray attenuation potency and favorable photoluminescence show great promise for biomedical research and disease diagnosis.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine, Jiangsu University, Zhenjiang, People's Republic of China.

ABSTRACT
X-ray computed tomography (CT) is the most commonly used imaging technique for noninvasive diagnosis of disease. In order to improve tissue specificity and prevent adverse effects, we report the design and synthesis of iodine-doped carbon dots (I-doped CDs) as efficient CT contrast agents and fluorescence probe by a facile bottom-up hydrothermal carbonization process. The as-prepared I-doped CDs are monodispersed spherical nanoparticles (a diameter of ~2.7 nm) with favorable dispersibility and colloidal stability in water. The aqueous solution of I-doped CDs showed wavelength-dependent excitation and stable photoluminescence similar to traditional carbon quantum dots. Importantly, I-doped CDs displayed superior X-ray attenuation properties in vitro and excellent biocompatibility. After intravenous injection, I-doped CDs were distributed throughout the body and excreted by renal clearance. These findings validated that I-doped CDs with high X-ray attenuation potency and favorable photoluminescence show great promise for biomedical research and disease diagnosis.

No MeSH data available.


The optical properties of the I-doped CDs.Notes: (A and B) UV–Vis absorbance and PL emission spectra of the I-doped CDs, respectively. The inset of (A) shows a diluted aqueous solution containing the as-prepared I-doped CDs. The PL emission spectra show the results of using progressively longer excitation wavelengths, from 330 to 400 nm in 10 nm increments. (C) The effect of molar ratio of glycine and iodixanol on the PL intensity. (D) The Tyndall effect exhibited by the I-doped CDs in aqueous solution.Abbreviations: I-doped CDs, iodine-doped carbon dots; UV–Vis, ultraviolet–visible; PL, photoluminescence; Q, quartz.
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f5-ijn-10-6943: The optical properties of the I-doped CDs.Notes: (A and B) UV–Vis absorbance and PL emission spectra of the I-doped CDs, respectively. The inset of (A) shows a diluted aqueous solution containing the as-prepared I-doped CDs. The PL emission spectra show the results of using progressively longer excitation wavelengths, from 330 to 400 nm in 10 nm increments. (C) The effect of molar ratio of glycine and iodixanol on the PL intensity. (D) The Tyndall effect exhibited by the I-doped CDs in aqueous solution.Abbreviations: I-doped CDs, iodine-doped carbon dots; UV–Vis, ultraviolet–visible; PL, photoluminescence; Q, quartz.

Mentions: The optical properties of the I-doped CDs were characterized using UV–Vis and PL spectrum (Figure 5). No obvious absorption peak could be observed in the UV–Vis spectrum (Figure 5A). The aqueous solution was pale yellow and transparent in daylight, but emitted bright blue fluorescence under UV excitation (inset, Figure 5A). The maximum emission at 475 nm was observed under 370 nm excitation. Additionally, the PL emission of the I-doped CDs, including the wavelength and intensity in well-regulated mode within the excitation range of 330–510 nm, was wavelength-dependent excitation (Figure 5B). Although the emission peak gradually shifted from 450 to 550 nm with increasing excitation wavelength, the intensity of emission increased and reached a maximum at 390 nm, beyond which the emission intensity gradually decreased. Figure 5C shows the effect of ratio of glycine and iodixanol on the PL of I-doped CDs. When the amount of iodine source equaled that of glycine (surface passivation), the PL intensity of I-doped CDs reached the maximum. The aqueous solution of I-doped CDs exhibited a long-term homogeneous phase without any noticeable precipitation at room temperature. To investigate the dispersibility in water, we used a beam of red light to illuminate the aqueous solution and observe the Tyndall effect clearly (as shown in Figure 5D). These results verified that the prepared I-doped CDs possessed superior fluorescent properties and dispersibility in aqueous solutions.


Engineering iodine-doped carbon dots as dual-modal probes for fluorescence and X-ray CT imaging.

Zhang M, Ju H, Zhang L, Sun M, Zhou Z, Dai Z, Zhang L, Gong A, Wu C, Du F - Int J Nanomedicine (2015)

The optical properties of the I-doped CDs.Notes: (A and B) UV–Vis absorbance and PL emission spectra of the I-doped CDs, respectively. The inset of (A) shows a diluted aqueous solution containing the as-prepared I-doped CDs. The PL emission spectra show the results of using progressively longer excitation wavelengths, from 330 to 400 nm in 10 nm increments. (C) The effect of molar ratio of glycine and iodixanol on the PL intensity. (D) The Tyndall effect exhibited by the I-doped CDs in aqueous solution.Abbreviations: I-doped CDs, iodine-doped carbon dots; UV–Vis, ultraviolet–visible; PL, photoluminescence; Q, quartz.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644166&req=5

f5-ijn-10-6943: The optical properties of the I-doped CDs.Notes: (A and B) UV–Vis absorbance and PL emission spectra of the I-doped CDs, respectively. The inset of (A) shows a diluted aqueous solution containing the as-prepared I-doped CDs. The PL emission spectra show the results of using progressively longer excitation wavelengths, from 330 to 400 nm in 10 nm increments. (C) The effect of molar ratio of glycine and iodixanol on the PL intensity. (D) The Tyndall effect exhibited by the I-doped CDs in aqueous solution.Abbreviations: I-doped CDs, iodine-doped carbon dots; UV–Vis, ultraviolet–visible; PL, photoluminescence; Q, quartz.
Mentions: The optical properties of the I-doped CDs were characterized using UV–Vis and PL spectrum (Figure 5). No obvious absorption peak could be observed in the UV–Vis spectrum (Figure 5A). The aqueous solution was pale yellow and transparent in daylight, but emitted bright blue fluorescence under UV excitation (inset, Figure 5A). The maximum emission at 475 nm was observed under 370 nm excitation. Additionally, the PL emission of the I-doped CDs, including the wavelength and intensity in well-regulated mode within the excitation range of 330–510 nm, was wavelength-dependent excitation (Figure 5B). Although the emission peak gradually shifted from 450 to 550 nm with increasing excitation wavelength, the intensity of emission increased and reached a maximum at 390 nm, beyond which the emission intensity gradually decreased. Figure 5C shows the effect of ratio of glycine and iodixanol on the PL of I-doped CDs. When the amount of iodine source equaled that of glycine (surface passivation), the PL intensity of I-doped CDs reached the maximum. The aqueous solution of I-doped CDs exhibited a long-term homogeneous phase without any noticeable precipitation at room temperature. To investigate the dispersibility in water, we used a beam of red light to illuminate the aqueous solution and observe the Tyndall effect clearly (as shown in Figure 5D). These results verified that the prepared I-doped CDs possessed superior fluorescent properties and dispersibility in aqueous solutions.

Bottom Line: Importantly, I-doped CDs displayed superior X-ray attenuation properties in vitro and excellent biocompatibility.After intravenous injection, I-doped CDs were distributed throughout the body and excreted by renal clearance.These findings validated that I-doped CDs with high X-ray attenuation potency and favorable photoluminescence show great promise for biomedical research and disease diagnosis.

View Article: PubMed Central - PubMed

Affiliation: School of Medicine, Jiangsu University, Zhenjiang, People's Republic of China.

ABSTRACT
X-ray computed tomography (CT) is the most commonly used imaging technique for noninvasive diagnosis of disease. In order to improve tissue specificity and prevent adverse effects, we report the design and synthesis of iodine-doped carbon dots (I-doped CDs) as efficient CT contrast agents and fluorescence probe by a facile bottom-up hydrothermal carbonization process. The as-prepared I-doped CDs are monodispersed spherical nanoparticles (a diameter of ~2.7 nm) with favorable dispersibility and colloidal stability in water. The aqueous solution of I-doped CDs showed wavelength-dependent excitation and stable photoluminescence similar to traditional carbon quantum dots. Importantly, I-doped CDs displayed superior X-ray attenuation properties in vitro and excellent biocompatibility. After intravenous injection, I-doped CDs were distributed throughout the body and excreted by renal clearance. These findings validated that I-doped CDs with high X-ray attenuation potency and favorable photoluminescence show great promise for biomedical research and disease diagnosis.

No MeSH data available.