DNA Hairpins as Temperature Switches, Thermometers and Ionic Detectors

Abstract

Temperature is of major importance in most branches of science and technology as well as in everyday life, and with the miniaturization of electronic devices and the increasing ability to make research into small-scale systems, a specific need for very small thermostats and thermometers has been created. Here we describe how DNA molecules can be used as nanoscale sensors to meet these requirements. We illustrate how the hybridization kinetics between bases in DNA molecules combined with conformational changes of the DNA backbone can be exploited in the construction of simple but versatile temperature switches and thermometers, which can be built into electronic systems. DNA based sensors are at the same time applicable as ion detectors to monitor the chemical environment of a specific system.

Homogeneous Electrochemical Assay for Real‐time Monitoring of Exonuclease III Activity Based on a Graphene Monolayer

“…The method consists of a hairpin‐structured DNA substrate (hsDNA) in which a methylene blue (MB) redox probe is covalently bound (5’ MB–GGCCGAGC TTTTTT GCTCGGCC–3’) at the 5’ end of the DNA. Poly T (TTTTTT) loop sequence in the middle of hsDNA was chosen because of the proper back‐folding for the stability of the stem‐loop structure at room temperature ,. In the presence of an exonuclease III (Exo III), the enzyme selectively digests the hsDNA from the 3’ terminus until double‐stranded DNA part is depleted, which thereby results in a single‐stranded DNA (ssDNA) fragment.…”

Thermoresponsive Nanodevices in Biomedical Applications

“…These DNA molecules have been applied as temperature sensors on a nanometric scale, for example like temperature switches and thermometers or environment sensors. High sensitivity can be obtained in specifically desired temperature ranges . The synthesis of hp‐DNA can be easily done by amplifying predefined DNA sequences by polymerase chain reaction (PCR) …”

“…High sensitivity can be obtained in specifically desired temperature ranges. [42] The synthesis of hp-DNA can be easily done by amplifying predefined DNA sequences by polymerase chain reaction (PCR). [43] Some of the smart nanosystems presented here are not only composed of thermoresponsive units, but also of other building blocks that have a structural function and contribute to the smartness of the system acting as triggers or labels.…”

Submicrometer-Sized Thermometer Particles Exploiting Selective Nucleic Acid Stability

“…[ 1,9 ] Nucleic acids offer unique opportunities to the development of nanothermometry, enhanced by the ease of synthesizing artifi cial nucleic acid sequences and detecting them by routine bioanalytical techniques. [ 10 ] Deoxyribonucleic acid (DNA) has been already exploited in the construction of thermometers, mostly based on fl uorescence measurements. [ 10,11 ] Although the use of DNA provides exceptional versatility, these thermometers present some drawbacks such us as low sensitivity or systematic errors due to fl uorescence fl uctuations.…”

“…[ 10 ] Deoxyribonucleic acid (DNA) has been already exploited in the construction of thermometers, mostly based on fl uorescence measurements. [ 10,11 ] Although the use of DNA provides exceptional versatility, these thermometers present some drawbacks such us as low sensitivity or systematic errors due to fl uorescence fl uctuations. [ 1 ] Moreover, the measurement involves realtime temperature read-out, which is impossible in some situations, such as underground temperature measurements for geothermal reservoir exploration and monitoring.…”