Sulforhodamine b

Sodium alginate, sodium periodate and ethylene glycol were purchased from J&K Scientific Ltd. (Beijing, China). Polyethyleneimine solution was obtained from Sigma-Aldrich Co. (St. Louis, MO, USA). Opti-MEM reduced-serum medium was supplied by Life Technologies (Carlsbad, CA, USA). Lipofectamine 2000 was provided by Invitrogen (New York, NY, USA). Sulforhodamine B was purchased from Macklin Ltd. (Shanghai, China). dsRNA (sense strand: 5′-UGGCAGUGUCUUAGCUGGUUGU-3′ and antisense strand: 5′-AACCAGCUAAGACACUGCCAUU-3′), ssRNA (inhibitor) (strand: 5′-ACAACCAGCUAAGACACUGCCA-3′), negative control (sense strand: 5′-UUCUCCGAACGUGUCACGUTT-3′ and antisense strand: 5′-ACGUGACACGUUCGGAGAATT-3′, named as NC), fluorescein-labeled dsRNA (5′ end of the sense strand, FAM-dsRNA), fluorescein-labeled ssRNA inhibitor (5′ end of the sense strand, FAM-ssRNA), and fluorescein-labeled negative control (5′ end of the sense strand, FAM-NC) were synthesized and purified with HPLC by Sangon Biotech Co., Ltd. (Shanghai, China). DMEM medium and PRMI 1640 medium were obtained from Macgene Technology Co., Ltd. (Beijing, China). The solvents were purchased from J&K Scientific Ltd. (Beijing, China).

The chemicals were purchased
from different companies as follows: lead(II) iodide (PbI₂, 99%, Sigma-Aldrich), potassium iodide (KI, 99%, Macklin), isobutylamine
(C₄H₁₁N, 99.5%, Aladdin), hypophosphorous acid
(H₃PO₂, 50 wt % in H₂O, Macklin), n-butylamine (C₄H₁₁N, 99%, Aladdin),
β-phenylethylamine (C₈H₁₁N, 98%, Aladdin),
(R)-(+)-α-methylbenzylamine (C₈H₁₁N, 99%, Macklin), (S)-(−)-α-methylbenzylamine
(C₈H₁₁N, 99%, Aladdin), sodium hydroxide (NaOH,
98%, Macklin), methyl orange (C₁₄H₁₄N₃NaO₃S, AR, Tianjin Tianxin Fine Chemical Development Center),
congo red (C₃₂H₂₂N₆Na₂O₆S₂, Tianjin Institute of Chemical Reagents),
direct black 19 (C₃₄H₂₇N₁₃Na₂O₇S₂, Maya Reagent), sulforhodamine-B
(C₂₇H₂₉N₂NaO₇S₂, 85%, Macklin), ethylenediamine tetraacetic acid (C₁₀H₁₆N₂O₈, AR, Damao chemical reagent), p-quinone (C₆H₄O₂, 99%,
Maya Reagent), silver nitrate (AgNO₃, AR, Damao chemical
reagent), and isopropyl alcohol (C₃H₈O, AR,
Tian in Fuyu Fine Chemical Co., Ltd.). All chemical reagents were
used as received without further purification, and deionized (DI)
water (>18 MΩ) was used throughout the experiments.