Development of an iridium(III) complex as a G-quadruplex probe and its application for the G-quadruplex-based luminescent detection of picomolar insulin
Department of Chemistry
In this study, an unreported Ir(III) complex 1 was identified by screening as a versatile G-quadruplex probe. It exhibited highly selective response for different G-quadruplex DNA over double strand, single strand and triplex DNA. Compared with the organic G-quadruplex probe thioflavin T, complex 1 displays a longer lifetime, a larger Stokes shift, comparable G-quadruplex/ssDNA enhancement ratios, and higher G-quadruplex/triplex DNA enhancement ratios. In consideration of the encouraging G-quadruplex probe performance of complex 1, we employed 1 to develop a G-quadruplex-based detection system for the detection of insulin as a “proof-of-principle” concept. We also demonstrate an optimization process that enhanced the sensitivity of this sensing assay. Compared to previously reported methods, our “mix-and-detect” detection methodology is easy operated, quick, and cost-effective. A detection limit as low as 80 pM for insulin can be achieved by this sensing approach, with a linear relationship between luminescence intensity and insulin concentration established from 80 pM to 20 nM. Moreover, this assay could work effectively in diluted human serum.
Source Publication Title
American Chemical Society
Link to Publisher's Edition
Wang, M., Wang, W., Kang, T., Leung, C., & Ma, D. (2016). Development of an iridium(III) complex as a G-quadruplex probe and its application for the G-quadruplex-based luminescent detection of picomolar insulin. Analytical Chemistry, 88 (1). https://doi.org/10.1021/acs.analchem.5b04064