Luminescent and hydrophilic LaF₃–polymer nanocomposite for DNA detection

Abstract

Luminescent LaF 3 -Ce 3+ /Tb 3+ nanocrystals have been successfully prepared via a simple wet chemical technique. For the next bioapplication, these nanoparticles dispersed in cyclohexane have also been functionalized with poly(Stco-MAA), based on a designed oil-in-water microemulsion system. These polymer-coated nanospheres are water-soluble and bioconjugable. Unlike semiconductor quantum dots, the as-prepared lanthanum fluoride nanocrystals possess nonsize-dependent emissions and completely stable photocycles. With functionalized LaF 3 nanospheres as fluorescence probes, a fluorescence method was developed for the rapid quantitative analysis of DNA, due to the quenching effect of fluorescence by the DNA. Under optimum conditions, the fluorescence intensity was proportional to the concentration of the introduced DNA over the range 2.5-35 mg/mL for calf thymus DNA (ctDNA) and 2.5-30 mg/mL for fish sperm DNA (fsDNA), respectively.

Time-resolved luminescent biosensing based on inorganic lanthanide-doped nanoprobes

“…[182][183][184] As an alternative to Ln 3+chelates, the advantages of Ln 3+ -doped luminescent nanoprobes in bioassays have been utilized. [185][186][187] In the past years, many novel luminescent bioassay methods such as heterogeneous sandwich assay, competitive assay, DNA microarrays, magnetic separation-assisted assay and homogeneous FRET assay, have been established based on Ln 3+ -doped DSL nanoprobes, for the detection of pathogenic microorganisms, 188,189 nucleic acids, [190][191][192] drugs of abuse, 193,194 antibodies, [195][196][197] glucose, 198,199 and reactive oxygen species, 200 to name a few. However, these bioassays were performed under steady-state PL detection, and were somewhat limited by either the poor dispersibility or broad size distribution of the nanoprobes.…”

Intra/Inter‐Particle Energy Transfer of Luminescence Nanocrystals for Biomedical Applications

“…Depending on different dopants of lanthanide ions, rare-earth-doped nanoparticles typically function as energy donors, can provide tunable emission to fit any accepters in energy transfer nanocomposites. For DNA-sensitive study, Wang et al have developed a novel DNA fluorescence detection method based on the polymer-coated rare-earth-doped nanoparticles [46]. The fluorescence originated from Tb 3+ transitions of LaF 3 :Ce 3+ , Tb 3+ nanoparticles can be quenched by the presence of nucleic acids such as DNA.…”

G‐rich sequence‐functionalized polystyrene microsphere‐based instantaneous derivatization for the chemiluminescent amplified detection of DNA

“…Many alternative DNA detection assays have been developed by means of optical[18–26] (molecular beacons, fluorescent labels, DNA‐derivatized nanoparticles, conjugated polymers, etc. ), electrochemical[27–30] (redox‐active nucleic acids, redox polymers, enzymatic systems, etc.)…”

“…Wang L. et al . [26] employed functionalized LaF 3 nanospheres as the fluorescence probes for the quantitative analysis of DNA, based on the quenching effect of fluorescence by the DNA. However, this method cannot discriminate between different DNA sequences.…”