An oligonucleotide microarray for microRNA expression analysis based on labeling RNA with quantum dot and nanogold probe.

MicroRNAs (miRNAs) play important regulatory roles in animals and plants by targeting mRNAs for cleavage or translational repression. They have diverse expression patterns and might regulate various developmental and physiological processes. Profiling miRNA expression is very helpful for studying biological functions of miRNAs.

Detection of tumor marker CA125 in ovarian carcinoma using quantum dots.

Semiconductor quantum dots (QDs) offer several advantages over organic dyes in fluorescence-imaging applications, such as higher quantum yield, exceptional photostability, and a narrow, tunable, and symmetric emission spectrum. To explore whether QDs could specifically and effectively label tumor markers and be used in immunohistochemistry as a novel type of fluorescent probe, we used quantum dots with maximum emission wavelength 605 nm (QD605) to detect the ovarian carcinoma marker CA125 in specimens of different types (fixed cells, tissue sections, and xenograft piece). Additionally, we compared the photostability of QD signals with that of a conventional organic dye, FITC.

Colorimetric detection of protein microarrays based on nanogold probe coupled with silver enhancement.

This work presents a method for analyzing protein microarrays using a colorimetric nanogold probe coupled with silver enhancement (gold-silver detection). In this method, the gold nanoparticles were introduced to the microarray by the specific binding of the gold-conjugated antibodies or streptavidins and then coupled with silver enhancement to produce black image of microarray spots, which can be easily detected with a commercial CCD camera. The method showed high detection sensitivity (1 pg of IgG immobilized on slides or 2.

[Application of quantum dot to life science].

As an eminent representation of nanotechnology, quantum dot (semiconductor nanocrystal) has caught great interests of scientists in physics, chemistry, material science, and biology extensively. Although its application to life science has just been explored, valuable progresses have been achieved in both biomacromolecule labeling and coding recently. The progress in quantum dot synthesis, its spectroscopic and photoelectronic properties, and its potential application to life science are reviewed.