Aptamer Development for Cancer Diagnostic

Early diagnosis improves the prognosis for cancer patients by allowing early intervention to slow or prevent cancer development and lethality. Aptamers are short single-stranded oligonucleotides that have a length of about 25–80 bases. They are produced chemically and extracted using the systematic evolution of ligands by exponential enrichment (SELEX). The use of aptamers as diagnostic tools in cancer is highly recommended due to their ability to recognize various cancer-related molecules and biomarkers with high affinity and specificity. Despite the clear advantages of aptamers, the potential of aptamers in cancer diagnosis is yet to be reached. This chapter will present the best available knowledge on using aptamers as the biorecognition element in the development of cancer biosensors. We will first present the advantages of aptamers in cancer diagnosis as well as various types of SELEX methods with emphasis on clinically relevant samples such as serum, whole cells, and tissue slices. We will also cover the various aptamer detection platforms, such as colorimetric, fluorescence, and electrochemical platforms. Furthermore, the updates on aptamers specific to KRAS mutation detection in cancer will be reviewed. Finally, the future direction of aptamers in cancer diagnosis will also be discussed.