Colorimetric determination of the activity of methyltransferase based on nicking enzyme amplification and the use of gold nanoparticles conjugated to graphene oxide

• Published in: Mikrochimica acta (1966) Vol. 186; no. 8; p. 594
• Main Authors: Li, Zhi-Mei, Zhang, Xiao, Pi, Ting, Bu, Jin, Deng, Rui-Hong, Chi, Bao-Zhu, Zheng, Xiang-Juan
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.08.2019; Springer; Springer Nature B.V
• Subjects: Amplification; Analysis; Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Colorimetry; Crosslinking; Drug development; Enzymes; Gold; Graphene; Graphite; Microengineering; Nanochemistry; Nanoparticles; Nanotechnology; Original Paper; Transferases; Hairpin DNA; Crosslinking effect; Drug development; Nanomaterial; M. SssI activity
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-019-3690-4

A method is described for the colorimetric determination of the activity of CpG methyltransferase (M.SssI). It is based on (a) the crosslinking effect between dsDNA-modified gold nanoparticles (AuNPs) and graphene oxide (GO), and (b) an amplification reaction with the aid of a nicking enzyme. To avoid the aggregation of AuNPs (which would produce false signals), a hairpin DNA was connected to the AuNPs. Thus, the red color of the solution (measured at 530 nm) increases linearly with the activity of M.SssI from 0.2 to 60 U·mL −1 , and the limit of detection is 67 U·mL −1 . This is superior to some reported strategies. The method was successfully applied to analyze spiked serum samples. Conceivably, it represents a powerful tool for use in drug development and diagnosis. Graphical abstracts A method based on the conjugated cross-linking effect between dsDNA modified Au NPs and GO coupled with an amplification reaction of nicking enzyme has been developed for colorimetric detection of the activity of CpG methyltransferase (M.SssI)