Fluorescent Ag nanoclusters prepared in aqueous poly(acrylic acid-co-maleic acid) solutions: a spectroscopic study of their excited state dynamics, size and local environment

Abstract

Stable, fluorescent Ag nanoclusters were prepared in aqueous solutions of Na(+) salt of the carboxylate-rich polymer poly(acrylic acid-co-maleic acid) under brief spells of UV irradiation. The nanoclusters were nearly spherical, with diameters within 1.90 ± 0.50 nm, but displayed a prominent red edge excitation shift (REES) of fluorescence upon exciting within the visible absorption band, indicating heterogeneity of energy level distributions. Spectroscopic studies revealed that irrespective of whether the nanoclusters are excited in their UV or visible absorption bands, their fluorescence always ensues from the same manifold of emissive states, with a broad range of fluorescence lifetimes from ∼150 fs to 1 ns.

Validating the reconstruction of DNA silver nanoclusters induced by different DNA sequence via HPLC and exploring the optical properties of reconstructed DNA silver nanoclusters

“…[1][2][3] To prevent the formation of large nanoparticles, various protective ligands have been utilized in the stabilization of AgNCs. [4][5][6][7][8][9][10][11][12][13] The use of DNA as a stabilizing ligand for AgNCs (DNA AgNCs) was first reported in 2004, 14 and received particular attention because of its applications in molecular sensing and bio-imaging studies. [15][16][17][18][19][20][21][22][23][24][25][26] The specificity of DNA binding to its complementary strand has allowed the design of molecular beacons for DNA and mRNA detection using DNA-AgNCs.…”

Synthesis of highly stable fluorescent poly(methacrylic acid-co-itaconic)-protected silver nanoclusters and sensitive detection of Cu2+

“…18 To date, AgNCs synthesized by using polyelectrolyte template containing carboxylic functional groups possess high uorescence and great stability because the carboxylic groups can not only bind the metal ions but also manipulate the conformation of the polymer according to different pH solutions. [19][20][21][22] As we all know, copper, as one of the most fundamental trace elements and a vital cofactor for many enzymes in the human body, plays an irreplaceable role in some physiological processes. 12,13,18 Abnormal copper content may cause negative effects on human health and even serious diseases, such as Alzheimer's disease, Parkinson's disease, and motor neuron disease.…”