Magnetically driven helical hydrogel micromotor for tumor DNA detection

•Magnetically driven helical hydrogel micromotor based DNA probing system, exhibits the ability to detect the DNA released by apoptotic tumor cells with high efficiency.•The hydrogel network composed of polyvinyl alcohol (PVA) and melamine (MA) can effectively load magnetic nanoparticles and small-molecule fluorescent probes.•The micromotor shows excellent controllable motion towards the predetermined target site. The DNA released by apoptotic tumor cells is one of the cancer markers, which can be used for early diagnosis, and prognosis evaluation. How to detect tumor DNA in a non-invasive, quick, and simple manner is attracting booming research enthusiasm. Here, we proposed a DNA detection system based on a magnetic helical hydrogel (PVA/MA/Fe3O4) micromotor incorporating fluorescent probe SYBR Green. Combining the precise navigation capabilities of the magnetically driven helical micromotor with high sensitivity of nucleic acid dyes, the micromotor-based fluorescent probing system not only exhibits excellent controllable moving performance, but also responds to the DNA released by apoptotic tumor cells with high efficiency, holding great promise for directed DNA detection. [Display omitted]