Integrated dual-signal aptasensor based on magnet-driven operations and miniaturized analytical device for on-site analysis

A novel dual-signal sensing system was developed for on-site analysis. A custom-built miniaturized workstation coupled with a home-made magneto-electrochemical detection module was employed for electrochemical sensing. The miniaturized workstation could be controlled by smartphone and all devices and tools in this integrated dual-signal biosensing platform were portable, which applies to on-site analysis. Meanwhile, by simple separation, color responses could be captured by naked-eye observation to detect target even in the absence of any instrument. The differences in target amounts were converted into the color change of AuNPs dispersion and the current change on solid electrode. A particularly objective in developing such versatile dual-signal strategy is to offer an user-friendly, portable, time-saving and cost-effective analysis strategy. The feasibility of the naked-eye colorimetric/magneto-electrochemical biosensing strategy was exemplified by using ATP and Hg2+ as model target. The LOD of two targets in electrochemical unit were 5.203 pmol L−1 and 1.597 pmol L−1 (S/N = 3), respectively. More importantly, the versatile dual-signal platform possesses favorable extensibility and could realize on-demand fast screening of other targets by using appropriate aptamers.