Mptes

2-(N-morpholino)ethanesulfonic acid (MES, Sigma-Adrich, Darmstadt, Germany), 3-aminopropyltriethoxysilane (APTES, Sigma-Adrich), 3-mercaptopropyl triethoxysilane (MPTES, >95%, Sigma-Adrich), ammonium fluoride (NH₄F, >98% Fluka, Darmstadt, Germany), Atto 633-carboxy dye (Atto-Tec, Siegen, Germany), 4′,6-diamidino-2-phenylindole (DAPI, Thermo Fisher, Schwerte, Germany), block copolymer surfactant (Pluronic F127 (EO₁₀₆PO₇₀EO₁₀₆), Sigma-Aldrich), cetyltrimethyl-ammonium chloride (CTAC, 25% in H₂O, Sigma-Adrich), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC, >97%, Sigma-Adrich), N-hydroxysulfosuccinimide (sulfo-NHS, 98%, Sigma-Adrich), octadecyltrimethylammonium bromide (C₁₈Br, Sigma-Adrich), propidium iodide, tetraethylorthosilicate (TEOS, >98%, Sigma-Aldrich), triethanolamine (TEA, 98%, Fluka), triisopropylbenzene (TiPB, 96%, Sigma-Adrich). Oligomer 454 [42 (link)] and Mal-PEG-GE11 [41 (link)] were synthesized as described before. siRNA and miRNA duplexes were purchased from Axolabs GmbH (Kulmbach, Germany): control RNA (sense: 5-AuGuAuuGGccuGuAuuAGdTsdT-3′, antisense: 5′-CuAAuAcAGGCcAAuAcAUdTsdT-3), miR200c (sense: 5′-UCCAUCAUUACCCGGCAGUAUUA-3, antisense: 5′-UAAUACUGCCGGGUAAUGAUGGA-3).

MXene, synthesized according to a previous protocol [18 (link)], was diluted to 1 mg/ml with deionized water (DIW). The AuMGE was manufactured by SNI technology (South Korea) based on previous research [19 (link)], and the AuMGE surface was ultrasonically cleaned with acetone for 10 min. Then, 10 μl of 5% aminopropyltriethoxysilane (Sigma-Aldrich, USA) was applied to AuMGE for 11 min to form an NH₂ layer, and silane was activated by heating in an oven at 70 °C for 1 h. Thiol-modified (SH–) groups were generated by reacting 10 μl of 6-mercaptohexanoic acid (6-MHA, Sigma-Aldrich, USA) and activated AuMGE for 1 h. Then, 10 μl of 1 mg/ml MXene was added and maintained at room temperature for 12 h for the reaction to occur. Finally, 10 μl of 5% mercaptopropyltriethoxysilane (MPTES, Sigma-Aldrich, USA) was applied for 11 min to create a SH group-modified layer.
SH group-modified Zika virus envelope protein aptamer was diluted to 1 μM with DIW, and 10 μl was reacted with the SH layer of AuMGE for 3 h to deposit the aptamer and bind it through self-assembly. All reactions were carried out at room temperature, and the residue was removed with DIW and N₂ gas.