Fluorescence Enhanced Quantum Dots: Its Synthesis, Optical Properties, and Ecotoxicity Research

Abstract

Quantum dots (QDs) are normally based on the semiconductor materials and widely used in biosensing, bioimaging, biolabeling, and biotreatment for their excellent properties. The ecotoxicity research of QDs correspondingly kept in rising in recent years. CdTe and CdTe/ZnS QDs were prepared via an improved process in aqueous phase, morphology of QDs was characterized with transmission electron microscopy, and optical properties were investigated via fluorescence spectrum. Ecotoxicity of CdTe and CdTe/ZnS were assayed by measuring the inhibitory growth of Rhodococcus sp. strain C1 when QDs existed in broth culture, which was screened from sewage, and its morphology was characterized with optical microscope and scanning electron microscope. CdTe QDs showed strong inhibitory effect against growth of Rhodococcus sp. strain C1, and little growth was observed after 72h cultivation. CdTe/ZnS QDs showed prophasic inhibition before 36h, and growth recovery was observed after 48h of cultivation. Enhanced optical properties and decreasing ecotoxicity were validated after ZnS shell formation, these results indicated that CdTe/ZnS QDs with core-shell structure has great potential in bio-applications.

DNA Detection of Toxoplasma gondii with a Magnetic Molecular Beacon Probe via CdTe@Ni Quantum Dots as Energy Donor

“…In the past decades, one of the most prominent and fastest moving interfaces of nanotechnology was the synthesis and application of semiconductor nanomaterials (such as quantum dots (QDs)) in biological detection and bioimaging [1][2][3][4][5][6][7][8][9][10]. The QDs have preeminent photophysical and chemical properties [11]: (1) efficient quantum yield, high brightness, and stability of the QDs against photobleaching; (2) the luminescence properties of QDs, which can be controlled by size due to the quantum confinement; (3) the luminescence spectra of QDs that reveal narrow emission bands and large Stokes shifts; (4) in contrast to organic fluorophores or transition metal complexes that exhibit broad absorbance bands and require specific wavelength excitation, QDs can be excited by a common high-energy excitation wavelength, leading to the size-controlled luminescence.…”