When irradiated with nanosecond laser pulses, gold nanoparticles allow for manipulation or destruction of cells and proteins with high spatial and temporal precision. Gold nanorods are especially attractive, because they have an up-to-20-fold stronger absorption than a sphere of equal volume, which is shifted to the optical window of tissue. Thus, an increased efficiency of cell killing is expected with laser pulses tuned to the near infrared absorption peak of the nanorods. In contrast to the higher-absorption, experiments showed a reduced efficacy of cell killing. In order to explain this discrepancy, transient absorption of irradiated nanorods was measured and the observed change of particle absorption was theoretically analyzed. During pulsed irradiation a strong transient and permanent bleaching of the near-infrared absorption band occurred. Both effects limit the ability of nanorods to destroy cells by nanocavitation. The existence of nanocavitation and transient bleaching was corroborated by optoacoustic measurements.
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http://dx.doi.org/10.1117/1.JBO.17.5.058003 | DOI Listing |
Anal Chim Acta
February 2025
The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an, 710049, China. Electronic address:
Background: Plasmonic core-shell nanostructures with embedded internal markers used as Raman probes have attracted great attention in surface-enhanced Raman scattering (SERS) immunoassay for cancer biomarkers due to their excellent uniform enhancement. However, current core-shell nanostructures typically exhibit a spherical shape and are coated with a gold shell, resulting in constrained local field enhancement.
Results: In this work, we prepared a core-shell AuNR@BDT@Ag structure by depositing silver on the surface of Raman reporter-modified gold nanorods (AuNR).
ACS Sens
January 2025
Department of Clinical Laboratory of Sir Run Run Shaw Hospital, College of Biosystems Engineering and Food Science, Zhejiang University School of Medicine, Hangzhou 310058, People's Republic of China.
The rapid, simple, and sensitive detection of nucleic acid biomarkers plays a significant role in clinical diagnosis. Herein, we develop a label-free and point-of-care approach for isothermal DNA detection through the trans-cleavage activity of CRISPR-Cas12 and the growth of gold nanomaterials in agarose gel. The presence of the target can activate CRISPR-Cas12a to cleave single-stranded DNA, thus modulating the length and number of DNA sequences that mediate the growth of gold nanoparticles (AuNPs) or gold nanorods (AuNRs).
View Article and Find Full Text PDFMikrochim Acta
January 2025
College of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, 26 Yuxiang Road, Shijiazhuang, 050018, P. R. China.
An aptamer-antibody sandwich electrochemical immunosensor was studied. FeO/MWCNTs-COOH/Nafion was modified and fixed on a glassy carbon electrode to amplify electrical signals. The antibody was coupled with AuNPs to form conjugates.
View Article and Find Full Text PDFGels
January 2025
Department of Electrical Engineering, The City College of New York, 160 Convent Avenue, New York, NY 10031, USA.
A two-dimensional array of microfluidic ports with remote-controlled valve actuation is of great interest for applications involving localized chemical stimulation. Herein, a macroporous silicon-based platform where each pore contains an independently controllable valve made from poly(N-isopropylacrylamide) (PNIPAM) brushes is proposed. These valves are coated with silica-encapsulated gold nanorods (GNRs) for NIR-actuated switching capability.
View Article and Find Full Text PDFAnal Methods
January 2025
Defence Research and Development Establishment, Jhansi Road, Gwalior, Madhya Pradesh 474002, India.
A sandwich electrochemical immunosensor was proposed for the sensitive detection of protective antigen ( PA) toxin based on cadmium sulphide nanocrystals (CdS NCs) and polypyrrole-gold nanoparticle-modified multiwalled carbon nanotubes (PPy-AuNPs/MWCNTs). Herein, PPy-AuNPs/MWCNTs were used as a biocompatible and conducting matrix for immobilization of rabbit anti-PA antibody [RαPA antibody, capturing antibody (Ab1)] and to facilitate excellent electrical conductivity. PPy-AuNPs/MWCNTs were synthesized through a one-step chemical reaction of pyrrole and Au on the surface of MWCNTs.
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