LAUSR

Abstract Alteration in the concentration of guanine (G) and adenine (A) leads to various abnormalities in the metabolic process which causes various diseases. Therefore, it is still remains a challenge to establish an accurate, simple and accurate method for simultaneous detection of guanine and adenine. In this paper, using covalent organic frameworks (COFs) as a carrier and the amine functionalized reduced graphene oxide as charge transfer accelerator, layer molybdenum disulfide (MoS2) nanosheets are deposited on glassy carbon electrode (GCE) by simple physical stacking to fabricate a dual-signal amplification biosensor for simultaneous detection of adenine and guanine. Under optimized conditions, the electrochemical behaviors of guanine and adenine on the COFs/NH2-rG/MoS2 modified electrode were studied by cyclic voltammetry and differential pulse voltammetry. The sensor performs well in determining G and A at the same time with wide linear ranges of 0.5-150.0μM and 1.0-280μM and low detection limits of 0.51μM(S/N=3) and 0.44μM(S/N=3), respectively. The sensor was successfully used to assay G and A in thermally denatured herring sperm DNA, and the G/A ratio was calculated to be 0.79. The biosensor has the advantages of simplicity, speed, high sensitivity, good reproducibility, and long-term stability.