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Photoactivated drug delivery systems using gold nanoparticles provide the promise of spatiotemporal control of delivery that is crucial for applications ranging from regenerative medicine to cancer therapy. In this study, we use second harmonic generation (SHG) spectroscopy to monitor the light-activated controlled release of oligonucleotides from the surface of colloidal gold nanoparticles. MicroRNA is functionalized to spherical gold nanoparticles using a nitrobenzyl linker that undergoes photocleaving upon ultraviolet irradiation. The SHG signal generated from the colloidal nanoparticle sample is shown to be a sensitive probe for monitoring the photocleaving dynamics in real time. The photocleaving irradiation wavelength is scanned to show maximum efficiency on resonance at 365 nm, and the kinetics are investigated at varying irradiation powers to demonstrate that the nitrobenzyl photocleaving is a one-photon process. Additional characterization methods including electrophoretic mobility measurements, extinction spectroscopy, and fluorimetry are used to verify the SHG results, leading to a better understanding of the photocleaving dynamics for this model oligonucleotide therapeutic delivery system.
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http://dx.doi.org/10.1021/acs.langmuir.5b02199 | DOI Listing |
Anal Sci
September 2025
Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526, Japan.
Surface-enhanced Raman scattering (SERS) is a powerful analytical technique; however, its quantitative application has been limited by the instability of substrates and significant signal fluctuations. In this study, we demonstrated that 4-aminobenzenethiol (4-ATP) can be quantitatively detected through statistical analysis of SERS signal intensity distributions obtained using citrate-stabilized AuNPs, biotin-functionalized AuNPs, and gold nanoparticle (AuNP)-bound polystyrene (PS) microparticles. Raman spectra obtained in bulk aqueous solution under static conditions showed that the detection sensitivity of 4-ATP using AuNP-bound PS microparticles was approximately twice that achieved with citrate-stabilized AuNPs or biotin-modified AuNPs.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
Department of Chemistry, National Taiwan University, Taipei 106319, Taiwan.
The exclusive formation of artificial multicomponent assemblies remains a significant challenge, in contrast to the well-established organization observed in natural systems, due to intrinsic entropic constraints. To overcome this limitation, recent efforts have been focused on developing precision self-assembly strategies for the rational construction of such architectures. Here, we construct an ideal complementary pair of 2,2':6',2″-terpyridine (tpy)-based ligands by fine-tuning the substituent bulkiness, which enables the quantitative formation of robust nested cages through efficient dynamic heteroleptic complexation with multivalent coordination.
View Article and Find Full Text PDFLangmuir
September 2025
Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Kamrup, Assam 781039, India.
The efficient and sustainable remediation of contaminated water calls for catalytic systems that must clean broadly, endure widely, and last repeatedly. In this regard, we report the development of sulfonate-functionalized core-shell hydrogel beads embedded with synthesized gold nanoparticles (AuNPs) that exhibit intrinsic oxidase-like activity without requiring external light or chemical oxidants. The sulfonate ligands modulate the surface electronic environment of the AuNPs, facilitating singlet oxygen generation via a nonplasmonic, radiationless mechanism.
View Article and Find Full Text PDFAnal Chem
September 2025
College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
A series of molecular logic gates with multiple biocomputing capabilities have been successfully fabricated by using four antibiotic residues [tetracycline (TET), chloramphenicol (CHL), kanamycin (KAN), and streptomycin (STR)] as inputs. The lateral flow strip biosensor was utilized to realize the visual and portable sensing of logic events. Four basic logic gates (OR, AND, XOR, and INHIBIT) and three cascade logic circuits (OR-INHIBIT-AND, 3AND-OR, and XOR-INHIBIT-OR-AND) were constructed.
View Article and Find Full Text PDFMikrochim Acta
September 2025
Teaching & Research Department of Common Course, Shenyang Sport University, Shenyang, 110115, China.
A surface enhanced Raman scattering (SERS)-based sensing platform is devised integrating a TMB redox system for rapid dopamine detection. Gold nanobipyramids (Au NBPs), synthesized via the heat-mediated seed-mediated growth method, possess dual functionality of peroxidase-like activity and SERS activity. This enables them to catalyze the oxidation of TMB and simultaneously amplify the Raman signal of the oxidized TMB product (oxTMB).
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