A novel reconfigurable optical biosensor based on DNA aptamers and a DNA molecular beacon.
In order to alter a typical molecular aptamer beacon (MAB) to detect a different analyte there is currently a need to change the whole sensor unit including the expensive labeling fluorophores. In this work a DNA-based reconfigurable molecular aptamer beacon was developed. It is composed of two parts: a variable part and a constant part. The variable part comprises an aptamer strand and its complementary strand while the constant part is an oligonucleotide doubly labeled with a Förster Resonance Energy Transfer (FRET) pair and the two parts become joined via DNA hybridization. The sensor exists in two conformations: a folded (high FRET) and an unfolded (low FRET) in the absence and presence of the aptamer-target binding respectively. This sensor can be reconfigured by washing away the aptamer and the complementary strand using proper complementary strands, called washers. As a proof of the principle, a sensor that bound the enzyme thrombin, an analyte with a strong binding, was first constructed and then reconfigured to bind adenosine, selected as an analyte with a weak binding. We believe that the design is of universal use applicable to many types of aptamers.
Trace Analysis and Biosensor Research Center, Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand. chittanon.buranachai@gmail.com
Chittanon
C
Buranachai
Panote
P
Thavarungkul
Proespichaya
P
Kanatharana
D000241:Adenosine / Q000032:analysis / Q000378:metabolism; D052157:Aptamers, Nucleotide / Q000378:metabolism*; D015374:Biosensing Techniques / Q000379:methods*; D015342:DNA Probes / Q000737:chemistry* / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes / Q000737:chemistry* / Q000378:metabolism; D055620:Optical Phenomena; D013917:Thrombin / Q000032:analysis / Q000378:metabolism
D052157:Aptamers, Nucleotide; D015342:DNA Probes; D015345:Oligonucleotide Probes; D013917:Thrombin; D000241:Adenosine