The detection of nucleic acids in biofluids is essential for changing the paradigm of disease diagnosis. As there are very few nucleic acids present in human biofluids, a high sensitivity method is required to detect nucleic acids for disease diagnosis. The Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation is associated with non-small cell lung cancer. It is a point mutation and requires a highly selective detection technique. In this study, high sensitivity and selectivity were achieved for the detection of KRAS mutation using rolling circle amplification (RCA), atomic transfer radical polymerization (ATRP), mutS enzyme, and electrochemical sensors. Although RCA can isothermally amplify DNA, it has low selectivity for detecting single-base mismatch DNA, and its sensitivity is not suitable for circulating tumor DNA detection. The selectivity of RCA was improved by using mutS, which can bind specifically to point mutations. In addition, as a method of isothermal radical polymerization, ATRP was used to amplify the weak signal of RCA. Since RCA and ATRP reactions occur simultaneously, detection time was reduced, and the calculated detection limit was 3.09 aM. Computational and experimental analyses were conducted to verify each detection step and the combination of mutS, ATRP, and RCA. The experiment was performed using normal human serum samples for biological application, and the proposed detection method was confirmed to have excellent potential for diagnosing cancer patients.
Bibliographical noteFunding Information:
This study was supported by a Korea University Grant, the National Research Foundation of Korea ( NRF ) (grant no. NRF- 2016R1A5A1010148 and NRF- 2021R1C1C2008615 ) and the Korea Evaluation Institute of Industrial Technology (grant no. K G012001242701 ).
© 2022 Elsevier B.V.
- Atomic transfer radical polymerization
- Electrochemical sensing
- Molecular dynamics simulation
- MutS enzyme
- Rolling circle amplification
- Single nucleotide polymorphism
ASJC Scopus subject areas
- Biomedical Engineering