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Upconversion nanomaterials: synthesis, mechanism, and applications in sensing.

Chen J, Zhao JX - Sensors (Basel) (2012)

Bottom Line: Over the past decade, high-quality rare earth-doped upconversion nanoparticles have been successfully synthesized with the rapid development of nanotechnology and are becoming more prominent in biological sciences.The synthesis methods are usually phase-based processes, such as thermal decomposition, hydrothermal reaction, and ionic liquids-based synthesis.In this review, the synthesis of upconversion nanoparticles and the mechanisms of upconversion process will be discussed, followed by their applications in different areas, especially in the biological field for biosensing.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of North Dakota, Grand Forks, ND 58202, USA. jiao.chen@my.und.edu

ABSTRACT
Upconversion is an optical process that involves the conversion of lower-energy photons into higher-energy photons. It has been extensively studied since mid-1960s and widely applied in optical devices. Over the past decade, high-quality rare earth-doped upconversion nanoparticles have been successfully synthesized with the rapid development of nanotechnology and are becoming more prominent in biological sciences. The synthesis methods are usually phase-based processes, such as thermal decomposition, hydrothermal reaction, and ionic liquids-based synthesis. The main difference between upconversion nanoparticles and other nanomaterials is that they can emit visible light under near infrared irradiation. The near infrared irradiation leads to low autofluorescence, less scattering and absorption, and deep penetration in biological samples. In this review, the synthesis of upconversion nanoparticles and the mechanisms of upconversion process will be discussed, followed by their applications in different areas, especially in the biological field for biosensing.

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The schematic of the nucleotide sensor design [110].
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f13-sensors-12-02414: The schematic of the nucleotide sensor design [110].

Mentions: DNA/RNA analysis is of great importance in molecular biology, genetic, and molecular medicine. Great effects have been invested in the precise concentration detection, such as metal nanoparticle-based analysis [105–108]. In recent years, UCNs were also used for the sensitive detection of oligonucleotides. For example, van de Rijke et al. [52] and Corstjens et al. [109] used UCNs as direct labeling reagents to detect single strand nucleic acids. A new design of a nucleotide sensor by Zhang et al. [110] used UCN as energy donor and the other fluorophore as an energy acceptor in a sandwich assay format (Figure 13). In the presence of UCNs and IR irradiation, the fluorophore was brought close to the UCN and energy transfer took place, leading to the light emission from the fluorophore. The target oligonucleotide can be detected by monitoring the fluorophore emission. This sensor displayed high sensitivity (1.3 nM), high specificity, and self-calibration capability. A general aptasensor for detection of various target molecules was reported recently by Liu et al. [111], which was based on UCNs-graphene oxide FRET. This proposed design can be further extended for sensing other kinds of molecules as well as causing structure conformations of ssDNA, which have shown its great potential in clinical diagnostic and biosensing techniques.


Upconversion nanomaterials: synthesis, mechanism, and applications in sensing.

Chen J, Zhao JX - Sensors (Basel) (2012)

The schematic of the nucleotide sensor design [110].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376553&req=5

f13-sensors-12-02414: The schematic of the nucleotide sensor design [110].
Mentions: DNA/RNA analysis is of great importance in molecular biology, genetic, and molecular medicine. Great effects have been invested in the precise concentration detection, such as metal nanoparticle-based analysis [105–108]. In recent years, UCNs were also used for the sensitive detection of oligonucleotides. For example, van de Rijke et al. [52] and Corstjens et al. [109] used UCNs as direct labeling reagents to detect single strand nucleic acids. A new design of a nucleotide sensor by Zhang et al. [110] used UCN as energy donor and the other fluorophore as an energy acceptor in a sandwich assay format (Figure 13). In the presence of UCNs and IR irradiation, the fluorophore was brought close to the UCN and energy transfer took place, leading to the light emission from the fluorophore. The target oligonucleotide can be detected by monitoring the fluorophore emission. This sensor displayed high sensitivity (1.3 nM), high specificity, and self-calibration capability. A general aptasensor for detection of various target molecules was reported recently by Liu et al. [111], which was based on UCNs-graphene oxide FRET. This proposed design can be further extended for sensing other kinds of molecules as well as causing structure conformations of ssDNA, which have shown its great potential in clinical diagnostic and biosensing techniques.

Bottom Line: Over the past decade, high-quality rare earth-doped upconversion nanoparticles have been successfully synthesized with the rapid development of nanotechnology and are becoming more prominent in biological sciences.The synthesis methods are usually phase-based processes, such as thermal decomposition, hydrothermal reaction, and ionic liquids-based synthesis.In this review, the synthesis of upconversion nanoparticles and the mechanisms of upconversion process will be discussed, followed by their applications in different areas, especially in the biological field for biosensing.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of North Dakota, Grand Forks, ND 58202, USA. jiao.chen@my.und.edu

ABSTRACT
Upconversion is an optical process that involves the conversion of lower-energy photons into higher-energy photons. It has been extensively studied since mid-1960s and widely applied in optical devices. Over the past decade, high-quality rare earth-doped upconversion nanoparticles have been successfully synthesized with the rapid development of nanotechnology and are becoming more prominent in biological sciences. The synthesis methods are usually phase-based processes, such as thermal decomposition, hydrothermal reaction, and ionic liquids-based synthesis. The main difference between upconversion nanoparticles and other nanomaterials is that they can emit visible light under near infrared irradiation. The near infrared irradiation leads to low autofluorescence, less scattering and absorption, and deep penetration in biological samples. In this review, the synthesis of upconversion nanoparticles and the mechanisms of upconversion process will be discussed, followed by their applications in different areas, especially in the biological field for biosensing.

Show MeSH