A DNA-based two-way thermometer to report high and low temperatures

• Published in: Analytica chimica acta Vol. 1081; pp. 176 - 183
• Main Authors: Lee, Mei-Hwa, Lin, Hung-Yin, Yang, Chia-Ning
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 12.11.2019
• Subjects: Carbocyanines - chemistry; Cold Temperature; DNA; DNA - chemistry; DNA - genetics; Fluorescence; Fluorescent Dyes - chemistry; Hep G2 Cells; Hot Temperature; Humans; Inverted Repeat Sequences; Molecular beacon; Nucleic Acid Conformation; Oligodeoxyribonucleotides - chemistry; Oligodeoxyribonucleotides - genetics; Osmolar Concentration; Perylene - chemistry; Temperature probe; Thermometers; Molecular beacon; Temperature probe; DNA
• ISSN: 0003-2670; 1873-4324; 1873-4324
• DOI: 10.1016/j.aca.2019.07.039

Precise description of temperature at the microscale level is essential in many biological applications. In this study, we prepared a DNA-based thermometer that reports low and high temperatures by providing two distinct optical signals. The system is a molecular beacon that carries a loop and a stem, whose conformation is subject to change from a hairpin to a random coil when the temperature changes from low to high. A fluorophore, Cy5, and a quencher, BHQ3, are terminally labeled at the stem ends. Moreover, perylene is included in the middle of the 3′-end stem. The signaling state of Cy5 relies on the relative distance to BHQ3. However, the perylene emission is regulated by its microenvironment (i.e., the oligonucleotide or duplex state). With a temperature variation, the designed thermometer undergoes a change in conformation that leads to two signal patterns with Cy5/off and perylene/on at low temperature and Cy5/on and perylene/off at high temperature. The reversibility and biocompatibility of the thermometer design were examined for potential applications in biological systems. [Display omitted] •This works demonstrates a molecular beacon probe carrying Cy5 and perylene to report temperatures.•The signal pattern is Cy5/off and perylene/on at low temperature.•The signal pattern is Cy5/on and perylene/off at high temperature.•Ion strength effect of the proposed system was discussed.•The reversibility and biocompatibility of the design were also examined for its future application.