Light-gated cascade amplification DNA circuit under the encapsulation of a natural protein-derived facilitate nanocarrier for spatiotemporal sensing in living cells

Abstract

Although their higher order of signal amplification and outstanding design flexibility, the cascade amplification DNA circuits still face with uncontrollable initiation and unsatisfactory biological uptake in living cells. To address these challenges, two productive breakthroughs are proposed here. First, a special light-gated manner is introduced into an entropy-driven strand displacement reaction and hybridization chain reaction combined DNA circuit by simply inserting the sensing components with a photocleavage linker, whereby a spatiotemporal target recognition is allowed to overcome the pre-activation of the sensing process during intracellular delivery. Afterwards, a facilitate AS1411-aptamer functionalized nanocarrier prepared by crosslinking a natural protein is employed to encapsulate our sensing system to enhance the endocytosis efficiency and realize an effective biological targeting. When choosing a low abundance microRNA related cancer biomarker (let-7a) as a conceptual study, it arises to a finding that this biosensor owns favorable sensitivity and even admirable specificity for distinguishing single-base mutation with assistance of a weak acid dissociation event. Moreover, we demonstrate that this sensing means can work as a forceful imaging platform for identifying cancer cells and also responding the intratumoral targets in living bodies, paving a hopeful venue for cancer analysis.