Specific and Sensitive in Vitro and in Vivo Nucleic Acid Detection and Imaging Using Graphene Oxide-Based Biosensors Composed of Unnatural Synthetic Threose Nucleic Acid as Capture Probes

Abstract

The variation of nucleotide sequence in the human genome, for instance, single nucleotide mutation, can cause a number of human genetic diseases. Thus, rapid, accurate and sensitive detection of nucleic acids in complex biological matrices plays a significant role but remains a big challenge. Natural deoxyribonucleic acids (DNA)s have been widely used as biorecognition probes but they show some limitations including poor specificity and reproducibility, nuclease-induced enzymatic degradation, and reduced bioactivity on solid substrates. Herein, we present a stable and reliable biosensor (GO-TNA) composed of chemically modified TNA capture probes onto graphene oxide (GO) for detecting and imaging of target nucleic acids in vitro and in vivo, discriminating single nucleobase mismatch and monitoring target miRNA dynamic changes. Loading the TNA capture probes onto the GO substrate to form GO-TNA sensing platform for nucleic acid detection shows significant improvement by 1000 times in the detection limit when compared to TNA probes itself. This detection platform has a simple preparation method without expensive and laborious isolation procedures and can be obtained without complicated chemical reactions, which are critical advantages for real-time analysis. It is anticipated that success with this stable TNA-based GO sensing nanoplatform will bring new opportunities in the field of disease diagnosis for rapid and accurate detecting and imaging of a variety of disease-related nucleic acid molecules at the in vivo level. Apart from healthcare, they may also lead to potential applications in the areas of environmental analysis and food safety by using different sequences of the TNA-based capture probes for detecting pesticides, antibiotics, or even foodborne pathogenic agents.

Keywords: Unnatural TNAs, Capture probes, Biosensors, Graphene oxide, Nucleic acid detection