摘要
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.
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单位武汉大学