Nucleic acid-functionalized upconversion luminescence biosensor based on strand displacement-mediated signal amplification for the detection of trivalent chromium ions.

Background: Rapid industrial development has generated serious pollution, including the presence of toxic and harmful heavy metal ions. Among them, trivalent chromium ion (Cr) is a very important element that poses a threat to life and health in our industrial wastewater pollution. Thus, it is important to develop efficient fluorescence methods for Cr detection.

Upconversion luminescence nanosensor for detection of Fe and phosphate ion based on the inner-filter effect.

In this work, an upconversion luminescence (UCL) nanosensor for fast detection of ferric ion (Fe) and phosphate ion (Pi) is developed based on the inner-filter effect (IFE) between NaYF:Yb/Er upconversion nanoparticles (UCNPs) and Fe-hypocrellin B (HB) complex. Fe-HB complex has strong absorption band (450-650 nm), which overlaps with the green emission peak of UCNPs at 545 nm. By adding Fe and Pi, the UCNPs-HB system produces the red-shift change of absorption spectrum, which leads to the "on-off-on" process of IFE.

Paper-based LRET sensor for the detection of total heavy rare-earth ions.

Based on the mechanism of luminescence resonance energy transfer (LRET) and using a special single strand DNA as the recognition element, a portable paper-based sensor for the accurate detection of total heavy rare-earth ions (mainly Gd, Tb and Dy) concentration was proposed. The RNA cleaving-DNAzyme should recognize rare-earth ions to cleave RNA on DNA duplexes linking UCNPs and AuNPs, causing UCNPs and AuNPs to approach each other, inducing LRET, which attenuated the green upconversion luminescence (UCL) triggered by the 980 nm laser. UCL was captured by a charge-coupled device (CCD) image sensor and processed with the red-green-blue (RGB) image to quantitatively analyze heavy rare-earth ions in the samples.

Expression and single-nucleotide polymorphisms of the H-FABP gene in pigs.

Heart fatty acid-binding protein (H-FABP) belongs to a family of intracellular fatty acid-binding proteins that are involved in the transport of long-chain fatty acids. Previous studies have indicated that H-FABP is significantly associated with intramuscular fat (IMF) content in pig. In this study, we compared the mRNA and protein expression of H-FABP between Tibetan pig (with high IMF) and Large White pig (with low IMF).