Application of functionalized CdS nanoparticles as fluorescence probe in the determination of nucleic acids

Abstract

Nanometer-sized fluorescent particles were successfully synthesized. The nanoparticles have a narrow, tunable, symmetric emission spectrum and a broad, continuous excitation spectrum. They are also photochemically stable. A synchronous fluorescence method was developed for the rapid determination of DNA with functionalized CdS as a fluorescence probe, based on the synchronous fluorescence quenching of functionalized CdS in the presence of DNA. Maximum fluorescence is produced at pH 7.0, with maximum excitation and emission wavelengths of 360 and 620 nm, respectively. The maximum emission wavelength of synchronous fluorescence is 354 nm when delta lambda = 260 nm. Under optimum conditions, the calibration graphs are linear over the range 0-3.5 microg mL(-1) for calf thymus DNA (CT-DNA) and 0.2-3.0 microg mL(-1) for fish sperm DNA. The corresponding detection limit is 0.01 microg mL(-1) for CT-DNA and 0.02 microg mL(-1) for fish sperm DNA. The relative standard deviation of seven replicate measurements is 2.2% for 1 microg mL(-1) calf thymus DNA and 2.4% for 1 microg mL(-1) fish sperm DNA. The method is simple, rapid and sensitive. The recovery and relative standard deviation are very satisfactory.

Luminescent and hydrophilic LaF3–polymer nanocomposite for DNA detection

“…Numerous materials, such as organic fluorescent dyes (4)(5)(6)(7)(8), semiconductor quantum dots (9,10) and luminescent metal-ligand complexes (11)(12)(13)(14), have been widely used as fluorescent probes for DNA detection. However, there are still some intrinsic limitations in these materials.…”

Design of Fluorescent Materials for Chemical Sensing

“…242 Since then, QD-based approaches to fluorescent sensing have been used extensively for biosensing and labeling of biomolecules. [243][244][245][246] The application of QDs to fluorescent chemosensing of abiotic analytes was not demonstrated until 2002 by Chen and Rosenzweig. 229 They reported the analysis of Cu(II) and Zn(II) ions by CdS luminescent QDs capped with polyphosphate, L-cysteine, and triglycerol as selective probes in aqueous media.…”

“Turn off–on” phosphorescent biosensors for detection of DNA based on quantum dots/acridine orange

“…The commonly-used materials include ethidium bromide [34], rare earth complexes [35][36][37] and cyanine dyes [38,39]. In recent years, some nanomaterial probes including QDs have been successfully applied into detection of nucleic acids [41][42][43].…”

“…The introduction of fluorescent probes provides a powerful tool for research of nucleic acids. So far, many types of fluorescent probes have been applied into quantitative determination of nucleic acids [34][35][36][37][38][39][40][41][42][43]. The commonly-used materials include ethidium bromide [34], rare earth complexes [35][36][37] and cyanine dyes [38,39].…”