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Surface state-controlled C-dot/C-dot based dual-emission fluorescent nanothermometers for intra-cellular thermometry
摘要: Fluorescence-based nanothermometers have potential to offer accuracy in the measurement of temperature using non-contact approaches. Herein, a C-dot/C-dot based dual-emission temperature sensing platform is fabricated through the electrostatic self-assembly of two kinds of fluorescent CDs with opposite charges. This dual-emission platform consists of several nearly-spherical CDs with two emission centers in blue (440 nm) and orange (590 nm) regions. The orange fluorescence exhibits discernible response to external temperatures in the range of ~15 to 85 °C; on the other hand, the blue fluorescence remains nearly constant. A continuous fluorescence color change in response to temperature from orange to blue can be clearly observed by the naked eye. Thus, the as-prepared C-dot based dual-emission nanospheres can be used for optical thermometry with high reproducibility and sensitivity (0.93%/°C). Detailed characterization shows that temperature (in the 15–85 °C window) impacts the surface states of orange emissive CDs, leaving the blue emissive CDs unaffected. A model is proposed to explain the observations. Finally, by taking advantage of the excellent biocompatibility and stability, the CD based fluorescent nanothermometer is successfully used for the visual measurement of intracellular temperature variations.
关键词: intracellular thermometry,temperature sensing,nanothermometers,dual-emission,fluorescence,carbon dots
更新于2025-09-11 14:15:04
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Molecularly Imprinted Fluorescent Test Strip for Direct, Rapid, and Visual Dopamine Detection in Tiny Amount of Biofluid
摘要: Paper-based assays for detection of physiologically important species are needed in medical theranostics owning to their superiorities in point of care testing, daily monitoring, and even visual readout by using chromogenic materials. In this work, a facile test strip is developed for visual detection of a neurotransmitter dopamine (DA) based on dual-emission fluorescent molecularly imprinted polymer nanoparticles (DE-MIPs). The DE-MIPs, featured with tailor-made DA affinity and good anti-interference, exhibit DA concentration-dependent fluorescent colors, due to the variable ratios of dual-emission fluorescence caused by DA binding and quenching. By facile coating DE-MIPs on a filter paper, the DA test strips are obtained. The resultant test strip, like the simplicity of a pH test paper, shows the potential for directly visual detection of DA levels just by dripping a tiny amount of biofluid sample on it. The test result of real serum samples demonstrates that the DA strip enables to visually and semiquantitatively detect DA within 3 min by using only 10 μL of serum samples and with a low detection limit ((100–150) × 10?9 m) by naked eye. This work thus offers a facile and efficient strategy for rapid, visual, and on-site detection of biofluids in clinic.
关键词: molecular imprinting,dual-emission fluorescence,visual detection,paper-based assays,dopamine
更新于2025-09-10 09:29:36
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Dual-Emission Fluorescent Microspheres for the Detection of Biothiols and Hg2+
摘要: Dual-emission nanosensor for Hg2+ detection was prepared by coupling CA-AEAPMS on the surface of RBS-doped modified silica microspheres. The CA-AEAPMS was synthesized by using N-(β-aminoethyl)-γ-aminopropyl methyldimethoxysilane (AEAPMS) and citric acid as the main raw material. The obtained nanosensor showed characteristic fluorescence emissions of Rhodamine B (red) and CA-AEAPMS (blue) under a single excitation wavelength (360 nm). Upon binding to Hg2+, only the fluorescence of CA-AEAPMS was quenched, resulting in the ratiometric fluorescence response of the dual-emission silica microspheres. This ratiometric nanosensor exhibited good selectivity to Hg2+ over other metal ions, because of the amide groups on the surface of CA-AEAPMS serving as the Hg2+ recognition sites. The ratio of F450/F580 linearly decreased with the increasing of Hg2+ concentration in the range of 0 to 3 × 10?6 M, and a detection limit was as low as 97 nM was achieved. Then, the addition of three thiol-containing amino acids (Cys, Hcy, GSH) to the quenched fluorescence solution with Hg2+ can restore the fluorescence, and the detection limits of the three biothiols (Cys, Hcy, GSH) are 0.133 μM, 0.086 μM, and 0.123 μM, respectively.
关键词: dual-emission,fluorescence,silica microspheres
更新于2025-09-09 09:28:46