“…First, 25 mL of 1000 nM aptamer was denatured at 95 °C for 5 min, frozen in ice for 5 min, and equilibrated at room temperature for 5 min. Next, 25 mL of different concentrations of CsA (5,10,20,40, 100, 300, 500, 1000, and 5000 ng mL −1 ) were mixed thoroughly and incubated for 25 min at room temperature. Then, 50 mL of 0.2 g L −1 AuNPs was added to the different concentrations of CsA solution, mixed, and incubated for another 15 min at room temperature.…”