- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Dual-Color Plasmonic Nanosensor for Radiation Dosimetry
摘要： Radiation dosimeters are critical for accurately assessing the levels of radiation exposure of tumor sites and surrounding tissues and for optimizing therapeutic interventions as well as for monitoring environmental exposure. To fill the need for a simple, user-friendly and inexpensive dosimeter, we designed an innovative colorimetric nanosensor-based assay for detecting ionizing radiation. We show that hydroxyl radicals generated by ionizing radiation can be used to etch gold nanorods (AuNRs) and silver nanoprisms (AgNPRs), yielding reproducible color changes for radiation dose detection in the range of 50-2000 Rad, broad enough to cover doses used in hyperfractionated, conventional, and hypofractionated radiotherapy. This range of doses detected by this assay correlates with radiation induced DNA damage response in mammalian cells. Furthermore, this AuNR- and AgNPR-based sensing platform has been established in a paper format that can be readily adopted for a wide range of applications and translation.
关键词： Radiation dosimetry,gold nanorods,silver nanoprisms,dual-color nanosensor,colorimetric detection
更新于2025-09-23 15:19:57
-
Plasmonic Silver Nanoprism-Induced Emissive Mode Control between Fluorescence and Phosphorescence of a Phosphorescent Palladium Porphyrin Derivative
摘要： We have succeeded in significantly enhancing fluorescence from intrinsically phosphorescent palladium octaethylporphyrin (Pd-porphyrin) that has an intersystem crossing efficiency of ~1 by using silver nanoprisms (AgPRs). This was achieved by controlling the wavelength of localized surface plasmon (LSP) resonance of AgPRs and the distance between the Pd-porphyrin molecules and the AgPR surfaces. In addition to enhancing phosphorescence by spectrally overlapping the phosphorescence band with the LSP resonance band, tuning the LSP wavelength to approximately 520 nm led to the appearance of a new emission band around the wavelength corresponding to the fluorescent radiation. The appearance of fluorescence suggests that the nonradiative energy transfer from the singlet excited state of Pd-porphyrin to the LSP of AgPRs overcame the ultrafast intramolecular intersystem crossing to the triplet excited state, manifesting the spectral properties of the singlet excited state of Pd-porphyrin. The fluorescence nature of this radiation was strongly supported by lifetime measurements of the hybrids of Pd-porphyrin and AgPRs. Furthermore, the dependence of the emissive intensities on the distance between the Pd-porphyrin molecules and the AgPR surfaces showed interesting opposite trends. The fluorescence intensity was increased as the distance between the molecules and the AgPRs was decreased from 10.5 nm to 1 nm, while the phosphorescence intensity was decreased, which indicates that the LSP-induced fluorescence radiation process from Pd-porphyrin near the AgPRs outweighed the quenching by the AgPRs, even though the phosphorescence significantly suffered quenching.
关键词： silver nanoprisms,localized surface plasmon resonance,palladium porphyrin,phosphorescence,metal-enhanced fluorescence,fluorescence,intersystem crossing
更新于2025-09-19 17:13:59
-
Precise Control of Localized Surface Plasmon Wavelengths Is Needed for Effective Enhancement of Triplet-Triplet Annihilation-Based Upconversion Emission
摘要： In this study, we demonstrate that the localized surface plasmon (LSP) resonance of metal nanoparticles, depending strictly on the generating wavelength of LSP resonance, can have both beneficial enhancement and harmful quenching effects on a triplet-triplet annihilation-based upconversion (TTA-UC) emission. When the LSP resonance band of anisotropic silver nanoprisms spectrally overlapped with the photoexcitation wavelength of a sensitizer and the fluorescence of an emitter, an increase in the photoexcitation efficiency and an acceleration of the radiative decay rate were respectively induced, resulting in an effective enhancement in the TTA-UC emission. Furthermore, the overlapping with the photoexcitation wavelength led to a significant decrease (93%) in the threshold light excitation intensity, which greatly enhances the figure-of-merit in TTA-UC systems. However, when the LSP resonance band overlapped with the phosphorescence band of the sensitizer, the TTA-UC emission was extremely quenched, accompanied by the enhanced phosphorescence and the decreased phosphorescence lifetime. These results suggest that the decrease in the TTA-UC emission is a result of the competition between the triplet-triplet energy transfer to the emitter and the LSP-induced nonradiative energy transfer to the silver nanoprisms from the triplet-excited sensitizer. This discovery of the conflicting effects of LSP resonance provides an important guideline: a precise adjustment of LSP resonance wavelengths is needed for the efficient enhancement of TTA-UC emission. This requirement is different from those of other fluorescence systems such as single downconverted fluorophores and lanthanide-based upconversion nanoparticles.
关键词： solid state,fluorescence,phosphorescence,silver nanoprisms,localized surface plasmon resonance,triplet-triplet annihilation,photon upconversion
更新于2025-09-10 09:29:36
-
Optical sensing platform for colorimetric determination of silver nanoprisms and its application for hydrogen peroxide and glucose detections using a mobile device camera
摘要： Silver nanoprisms (AgNPrs) have a unique localized surface plasmon resonance, resulting in strong absorption and scattering within the visible light region. In this work, we propose the image acquisition from colloidal solutions of AgNPrs using a combination of transmitted and scattering lights. The developed measurement technique could be carried out by separately recording transmitted and scattering images of the solutions, using a mobile device camera prior to calculation of empirical absorption value (IA). IA value of green for AgNPrs solutions was found in agreement with the absorption spectra obtained using a conventional spectroscopic technique. This technique was utilized for the quantifications of hydrogen peroxide and glucose. The good linearities between ΔIA and those typical analytes were observed. The limit of detection for typical biosensor of glucose was 19.8 μM. As such, we expect the methodology herein developed for hydrogen peroxide and glucose determinations by means of monitoring the color change of transmitted and scatting images from solutions, to contribute to the development of simple, rapid, and reliable detection systems to be further applied in biochemical analysis and clinical diagnosis, as well as in household biosensor applications.
关键词： silver nanoprisms,glucose sensor,hydrogen peroxide sensor,localized surface plasmon resonance,colorimetric method
更新于2025-09-09 09:28:46