Upconversion Luminescence-Initiated and GSH-Responsive Self-Driven DNA Motor for Automatic Operation in Living Cells and In Vivo

In light of the worthy design flexibility and the good signal amplification capacity, the recently developed DNA motor(especially the DNA walker)-based fluorescent biosensors can offer an admirable choice for realizing bioimaging. However, this attractive biosensing strategy not only has the disadvantage of uncontrollable initiation but also usually demands the supplement of exogenous driving forces. To handle the above obstacles, some rewarding solutions are proposed here. First, on the surface of an 808nm near-infrared light-excited low-heat upconversion nanoparticle, a special ultraviolet upconversion luminescence-initiated three-dimensional (3D) walking behavior is performed by embedding a photocleavage linker into the sensing elements, and such light-controlled target recognition can perfectly overcome the pre-triggering of the biosensor during the biological delivery to significantlyboost the sensing precision. After that, a peculiar self-driven walking pattern is constructed by employing MnO2nanosheets as anadditional nanovector to physically absorb the sensing frame, for which the reduction of the widespread glutathione in the biologicalmedium can bring about sufficient self-supplied Mn2+to guarantee the walking efficiency. By selecting an underlying next-generationbroad-spectrum cancer biomarker (survivinmessenger RNA) as the model target, we obtain that the newly formed autonomous 3DDNA motor shows a commendable sensitivity (where the limit of detection is down to 0.51 pM) and even an outstanding specificity for distinguishing single-base mismatching. Beyond this sound assay performance, our sensing approach is capable of working as a powerful imaging platform for accurately operating in various living specimens such as cells and bodies, showing a favorable diagnostic ability for cancer care.

Automated summary

The recently developed DNA motor-based fluorescent biosensors offer a promising choice for bioimaging due to their design flexibility and signal amplification capacity. However, the uncontrollable initiation and the need for exogenous driving forces are major drawbacks. To overcome these obstacles, this study proposes two rewarding solutions involving light-controlled target recognition and self-driven walking pattern. The results demonstrate commendable sensitivity and specificity of the sensing approach, making it a powerful imaging platform with potential diagnostic ability for cancer care.