A portable visual detection method based on a target-responsive DNA hydrogel and color change of gold nanorods

A new method based on a functional DNA crosslinked hydrogel as a target-responsive unit and gold nanorods (AuNRs) as a multicolor signal readout circuit was developed for the sensitive and visual detection of different targets. The color variation of the AuNR solution was correlated with the concentration of the target. This system can be extended to detect various targets by designing the corresponding target-responsive DNA hydrogels.