Fig. 4.

(A) (a) Schematic of target-switchable DNA hydrogels coupled with a Bi₂Sn₂O₇/Bi₂S₃ heterojunction based on in situ anion exchange for photoelectrochemical detection of DNA. (b) PEC response of sensor to different target concentrations. Copyright 2021, The Royal Society of Chemistry. (B) (a) Schematic of imaging ellipsometry biosensor based on DNA hydrogelation for multiplexed exosomal miRNA detection. (b) Linear range of the IES for the multiplexed detection of let-7a, miR-375, and miR-21. Copyright 2020, American Chemical Society. C. Schematic of the electrochemical biosensing platform based on hybrid DNA hydrogel using for miR-21detection. Copyright 2018, Elsevier. (D) (a) Schematic of target miRNA 155-Induced Duplex-Specific Nuclease Signal Amplification Possess, (b) schematic of SERS Platform construction, and (c) preparation of TB Trapped 3D DNA Hydrogel. Copyright 2017, American Chemical Society.