Inorganic Nanoparticles as Donors in Resonance Energy Transfer for Solid-Phase Bioassays and Biosensors

Abstract

Bioassays for the rapid detection and quantification of specific nucleic acids, proteins, and peptides are fundamental tools in many clinical settings. Traditional optical emission methods have focused on the use of molecular dyes as labels to track selective binding interactions and as probes that are sensitive to environmental changes. Such dyes can offer good detection limits based on brightness but typically have broad emission bands and suffer from time-dependent photobleaching. Inorganic nanoparticles such as quantum dots and upconversion nanoparticles are photostable over prolonged exposure to excitation radiation and tend to offer narrow emission bands, providing a greater opportunity for multiwavelength multiplexing. Importantly, in contrast to molecular dyes, nanoparticles offer substantial surface area and can serve as platforms to carry a large number of conjugated molecules. The surface chemistry of inorganic nanoparticles offers both challenges and opportunities for the control of solubility and functionality for selective molecular interactions by the assembly of coatings through coordination chemistry. This report reviews advances in the compositional design and methods of conjugation of inorganic quantum dots and upconversion nanoparticles and the assembly of combinations of nanoparticles to achieve energy exchange. Our interest is the exploration of configurations where the modified nanoparticles can be immobilized to solid substrates for the development of bioassays and biosensors that operate by resonance energy transfer (RET).

Enhanced Immunoassay Using a Rotating Paper Platform for Quantitative Determination of Low Abundance Protein Biomarkers

“…Water-soluble glutathione-coated QDs (GSH-QD) were prepared using a previously reported method . The immobilization MB probes on QD surfaces was done using the magnetic loading method .…”

Energy Pumping by Surface Collectors on Upconversion Nanoparticles for Extended Transfer and Efficient Self-Evaluable Photodynamic Therapy

“…Supporting Information is available and includes the synthesis of UCNP-Cy3, UCNP-DNA-Cy3, UCNP-peptide-QSY7 and UCNP-peptide-Cy3. 5…”

“…The multiplex upconversion emissions and relatively low background make upconversion nanoparticle (UCNP) a popular nanomaterial for designing bioprobes in bioanalysis and cancer therapy recently [1][2][3][4][5][6] . Taking UCNP as energy donor and dye attached on its surface as energy acceptor, different "off-on" upconversion bioprobes have been designed for sensing of small molecules such as metal ions 7,8 , ATP 9 , free radicals 10,11 , pH 12,13 , sulfur compounds 14 , and drug metabolites 15,16 .…”

Resonance Energy Transfer Mediated by Metal–Dielectric Composite Nanostructures

“…The size dependence is taken to enter only through the intraband contribution specifically through the damping term, Γ; the size dependence of the interband contribution has been theoretically shown to be negligible for particles larger than 2 nm. 9,10 We adopt the phenomenological size correction to gamma,…”