Sodium citrate c6h5na3o7

The silver nanoparticles were prepared by a seedless photo-assisted citrate reduction method under the irradiation of blue light-emitting diodes (LEDs) according to a previously reported method [25 (link)]. Silver nitrate (AgNO₃) and sodium citrate (C₆H₅Na₃O₇) with a normal purity of 99% were obtained from Sigma-Aldrich, Oakville, ON, Canada. Millipore^® water (18.2 MΩ·cm) was used in all experiments. In brief, 1 mL of sodium citrate (4.5 × 10⁻¹ M) and 1 mL of silver nitrate (1.0 × 10⁻² M) were mixed with 98.0 mL of pure water. The mixture was subsequently irradiated with 30 blue LEDs (Inspired LED lightening bars and strips blue with λ_max = 465 nm and average power = 240 mW, Mouser Electronics Inc., Kitchener, ON, Canana) at room temperature. Silver colloids containing a mixture of decahedral nanoparticles (app. 60% (Mouser electronics, Kitchener, ON, Canada), as determined by Transmission Electron Microscopy, TEM) and nanoparticles of triangular shape (Figure 1a,b), were obtained after 24 h of irradiation. The silver nanoparticle suspension was concentrated 10 times by centrifugation at 1800× g for 30 min prior to use.

The aptamer sequences used in this study were as follows:
SDM 5′-GAGGGCAACGAGTGTTTATAGA-3′[21] (link);
KAN: 5′-TGGGGGTTGAGGCTAAGCCGA-3′[18] (link);
ADE: 5′-ACCTGGGGGAGTATTGCGGAGGAAGGT-3′[22] (link).
The ssDNA oligonucleotides were synthesized by the Shanghai Sangon Biotechnology Co. Ltd. (Shanghai, China). The lyophilized powder was resuspended in 20 mM Tris-HCl containing 20 mM NaCl and 5 mM KCl and stored at 4°C until use. The oligonucleotide concentration was determined by measuring the UV absorbance at 260 nm. Chloroauric acid (HAuCl₄) and sodium citrate (C₆H₅Na₃O₇) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Sulfadimethoxine (SDM) and kanamycin (KAN) were purchased from Dr. Ehrenstorfer GmbH (Augsburg, Germany). Adenosine (ADE) was purchased from Amresco (Solon, OH). All remaining common chemicals, including NaCl, KCl and Tris-HCl, were purchased from the Beijing Chemical Reagent Company (Beijing, China). All chemicals were of at least analytical grade. A 96-well polystyrene microplate (12 strips of 8 wells) was purchased from Corning (Corning, NY). The water used in all experiments was purified using a Milli-Q system (Millipore, Bedford, MA, USA).