100 mL 0.001 mol L−1 hydrochloric acid solution, the SCMNPs
prepared above, and 3 mL of 1 mol L−1 KNO3 solution were mixed
together in a 250 mL breaker by ultrasonication for 10 min, and then
adjusted to pH 5 with diluted NaOH. After that the solution wastransferred to 500 mL three neck flask, and sodium dodecyl sulfate
was added until its final concentration remained at 7.5 mmol L−1.
The mixture was stirred at room temperature for 1 h. Subsequently,
the suspension was heated to 60 ◦C, and then 2 g dithizone was
added. After 1 h reaction under stirring, the obtained dithizone
modified magnetic nanoparticles were vacuum filtered, washed
with deionized water and ethanol sequentially for several times,
and finally dried at 40 ◦C under vacuum. Fig. 1 shows the synthesis
procedure for H2Dz-SCMNPs.