Titan 80 300 stem

Into a 35 mL microwave vessel with a stir bar, 48.5 mg CdCl₂, 100 mg sodium citrate dehydrate, 26 μL of MPA and 25 mL Millipore water were combined. The pH of this mixture was brought to 10.5 using 1 M NaOH, and then 11 mg of sodium tellurite and 18.9 mg of sodium borohydride were added. The vessel was capped and placed in a CEM Discover SP microwave synthesizer. The mixture was microwaved in Dynamic Mode at 100 °C, 250 psi, 300 W power, and high stirring for 10 min. QDs were purified three times via centrifugation through a 30K MWCO centrifuge filter at 2000g for 5 min, and finally redispersed in pH 10.5 Millipore water. Absorbance properties were detected with a Thermo Scientific Evolution 201 UV–Vis spectrophotometer. The absorbance was used to determine QDs’ molar concentration and size according to the literature.³⁰ Fluorescence spectroscopy measurements were collected using a PTI-Horiba QuantaMaster 400 fluorimeter. High-resolution transmission electron microscopy (HRTEM) images of QDs, that were drop-coated onto mesh copper grids with ultrathin carbon film on holey carbon support film (Ted Pella, Inc.), were obtained using a Titan 80–300 S/TEM, operating at 300 kV with a Gatan OneView imaging camera. Dynamic Light Scattering (DLS) measurements of MPA–QDs were performed using a Malvern Zetasizer Nano ZS instrument.