Integrating graphene oxide, functional DNA and nucleic-acid-manipulating strategies for amplified biosensing

Integrating functional DNA probes with graphene oxide (GO) has proved to be a productive approach to the design of optical biosensors that detect nucleic acids, proteins or small-molecule targets. This distinctive methodology neatly combines four intriguing properties associated with DNA and GO: • the functional versatility of DNA sequences as molecular receptors; • the ability of DNA to switch structural forms in a target-responsive manner; • the power of GO as a fluorescence quencher; and, • the differential affinity of GO for different structural forms of DNA. In recent years, several elegant signal-amplification strategies uniquely applicable to optical DNA-GO biosensors were reported and these amplified biosensors were productively employed to achieve ultrasensitive detection of diverse targets. This review highlights notable achievements in this budding research field and provides a perspective on where the field is heading.