Biomedical applications of nanoflares: Targeted intracellular fluorescence probes

• Published in: Nanomedicine 2019-04, Vol.17, p.342-358
• Main Authors: Chenab, Karim Khanmohammadi, Eivazzadeh-Keihan, Reza, Maleki, Ali, Pashazadeh-Panahi, Paria, Hamblin, Michael R, Mokhtarzadeh, Ahad
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - analysis; Animals; ATP detection; Biosensing Techniques - methods; Cancer cell detection; DNA, Single-Stranded - chemistry; DNA, Single-Stranded - genetics; Fluorescence Resonance Energy Transfer - methods; Fluorescent Dyes - chemistry; Gold - chemistry; Humans; Immobilized Nucleic Acids - chemistry; Immobilized Nucleic Acids - genetics; Inorganic ion detection; Metal Nanoparticles - chemistry; mRNA detection; Nanoflares; Neoplasms - diagnosis; Neoplasms - genetics; Nucleic acid hybridization; RNA, Messenger - analysis; RNA, Messenger - genetics; Targeted intracellular fluorescence probes
• ISSN: 1549-9634; 1549-9642; 1549-9642
• DOI: 10.1016/j.nano.2019.02.006

Nanoflares are intracellular probes consisting of oligonucleotides immobilized on various nanoparticles that can recognize intracellular nucleic acids or other analytes, thus releasing a fluorescent reporter dye. Single-stranded DNA (ssDNA) complementary to mRNA for a target gene is constructed containing a 3′-thiol for binding to gold nanoparticles. The ssDNA “recognition sequence” is prehybridized to a shorter DNA complement containing a fluorescent dye that is quenched. The functionalized gold nanoparticles are easily taken up into cells. When the ssDNA recognizes its complementary target, the fluorescent dye is released inside the cells. Different intracellular targets can be detected by nanoflares, such as mRNAs coding for genes over-expressed in cancer (epithelial-mesenchymal transition, oncogenes, thymidine kinase, telomerase, etc.), intracellular levels of ATP, pH values and inorganic ions can also be measured. Advantages include high transfection efficiency, enzymatic stability, good optical properties, biocompatibility, high selectivity and specificity. Multiplexed assays and FRET-based systems have been designed. Biomedical applications of nanoflares in biosensing. Nanoflares consist of oligonucleotides attached to gold nanoparticles that can release a fluorescent dye upon binding to their target. The dye excitation is wavelength matched to the plasmon resonance frequency of the nanoparticles. They are able to detect intracellular analytes such as mRNAs and ATP with high sensitivity, and can also respond to pH and metallic ions. [Display omitted]