Micro/nanoparticles containing densely packed gold nanoparticles (AuNPs) possess unique properties potentially useful for various biomedical applications. The micro/nanoparticles are conventionally produced by the bottom-up methods, which have limited capability for controlling the particle size, shape and structure. This article reports development of a top-down method that integrates layer-by-layer assembly and microcontact printing to fabricate disk-shaped microparticles named microdisks composed of densely packed AuNPs. This method allows precise control of not only the size, shape and structure of the microdisks but also the amount of the AuNPs in the microdisks. The microdisks can be loaded with different Raman reporters to generate characteristic surface-enhanced Raman scattering spectra under the near infrared excitation over a centimetre-scale lens-sample distance. Moreover, the microdisks can be attached to single live cells. This microdisk platform holds potential for multiplex Raman labelling of therapeutic cells for in vivo tracking of the cells.
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http://dx.doi.org/10.1039/c4nr01851f | DOI Listing |
Nat Methods
January 2025
Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA.
Super-resolution imaging of cell metabolism is hindered by the incompatibility of small metabolites with fluorescent dyes and the limited resolution of imaging mass spectrometry. We present ultrasensitive reweighted visible stimulated Raman scattering (URV-SRS), a label-free vibrational imaging technique for multiplexed nanoscopy of intracellular metabolites. We developed a visible SRS microscope with extensive pulse chirping to improve the detection limit to ~4,000 molecules and introduced a self-supervised multi-agent denoiser to suppress non-independent noise in SRS by over 7.
View Article and Find Full Text PDFA coherent concatenation of multiple solitary waves may lead to a stable infrared and visible broadband filament in a ceramic YAG polycrystal. This self-trapped soliton train is leveraged to implement self-referenced multiplex coherent anti-Stokes Raman scattering (SR-M-CARS) imaging. Simulations and experiments illustrating the filamentation process and the concatenation of focusing-defocusing cycles in ceramic and crystal YAG are presented.
View Article and Find Full Text PDFJ Pharm Anal
November 2024
Department of Pharmaceutical Analysis, ISF College of Pharmacy Moga, 142001, Punjab, India.
An optical biosensor is a specialized analytical device that utilizes the principles of optics and light in bimolecular processes. Localized surface plasmon resonance (LSPR) is a phenomenon in the realm of nanophotonics that occurs when metallic nanoparticles (NPs) or nanostructures interact with incident light. Conversely, surface-enhanced Raman spectroscopy (SERS) is an influential analytical technique based on Raman scattering, wherein it amplifies the Raman signals of molecules when they are situated near specific and specially designed nanostructures.
View Article and Find Full Text PDFBiosens Bioelectron
December 2024
State Key Laboratory of Food Science and Resources, School of Food Science and Technology, Jiangnan University, 214122, Wuxi, Jiangsu, People's Republic of China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, 214122, Wuxi, Jiangsu, People's Republic of China; International Joint Laboratory on Food Safety, Jiangnan University, 214122, Wuxi, Jiangsu, People's Republic of China. Electronic address:
Tetracycline antibiotics (TCs) are extensively used as broad-spectrum antimicrobials. However, their excessive use and misuse have led to serious accumulation in foods and environments, posing a significant threat to human health. To solve such public issue, we have designed a novel dual-mode detection method, integrating colorimetric sensing with surface-enhanced Raman scattering (SERS) technology, for sensitive and rapid evaluation on TCs.
View Article and Find Full Text PDFACS Sens
January 2025
Center for Biomedical-photonics and Molecular Imaging, Advanced Diagnostic-Therapy Technology and Equipment Key Laboratory of Higher Education Institutions in Shaanxi Province, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710126, China.
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