Molecular Beacon Lighting up on Graphene Oxide
- 18 April 2012
- journal article
- research article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 84 (9), 4192-4198
- https://doi.org/10.1021/ac300778s
Abstract
A molecular beacon (MB) is comprised of a fluorophore and a quencher linked by a DNA hairpin. MBs have been widely used for homogeneous DNA detection. In addition to molecular quenchers, many nanomaterials such as graphene oxide (GO) also possess excellent quenching efficiency. Most reported fluorescent sensors relied on DNA probes physisorbed by GO, which may suffer from nonspecific probe displacement and false positive signal: In this work, we report the preparation and characterization of a MB using graphene oxide (GO) as quencher, where an amino and FAM (6-carboxyfluorescein) dual labeled DNA was covalently attached to GO via an amide linkage. A major challenge was to remove noncovalently attached probes due to strong DNA adsorption by GO. While DNA desorption was favored at low salt, high pH, high temperature, and by using organic solvents, the cDNA was required to achieve complete desorption of noncovalently linked DNA probes. The DNA adsorption energy was measured using isothermal titration calorimetry, revealing the heterogeneous nature of GO. The covalent probe has a detection limit of 2.2 nM using a sample volume of 0.05 mL. With a 2 mL sample, the detection limit can reach 150 pM. The covalent probe is highly resistant to nonspecific probe displacement and will find applications in serum and cellular samples where high probe stability is demanded.Keywords
This publication has 59 references indexed in Scilit:
- DNA Sensing by Amplifying the Number of Near-Infrared Emitting, Oligonucleotide-Encapsulated Silver ClustersAnalytical Chemistry, 2011
- Molecular Engineering of DNA: Molecular BeaconsAngewandte Chemie-International Edition, 2009
- Nucleic Acid Beacons for Long-Term Real-Time Intracellular MonitoringAnalytical Chemistry, 2008
- Molecular Assembly of Superquenchers in Signaling Molecular InteractionsJournal of the American Chemical Society, 2005
- Direct Synthesis of an Oligonucleotide–Poly(phenylene ethynylene) Conjugate with a Precise One‐to‐One Molecular RatioAngewandte Chemie-International Edition, 2005
- Adaptation of inorganic quantum dots for stable molecular beaconsSensors and Actuators B: Chemical, 2004
- P53-dependent activation of a molecular beacon in tumor cells following exposure to doxorubicin chemotherapyCancer Biology & Therapy, 2004
- Single-mismatch detection using gold-quenched fluorescent oligonucleotidesNature Biotechnology, 2001
- Solid-Phase Synthesis of Doubly Labeled Peptide Nucleic Acids as Probes for the Real-Time Detection of HybridizationAngewandte Chemie-International Edition, 2000
- Molecular Beacons: Probes that Fluoresce upon HybridizationNature Biotechnology, 1996