1 octadecene ode

Lead bromide (PbBr₂, 99.999%, Alfa-Aesar), Cesium carbonate (Cs₂CO₃, 99.9%, Alfa-Aesar), 1-octadecene (ODE, 90%, Alfa-Aesar), oleic acid (OA, 90%, Sigma-Aldrich), oleylamine (OAm, 80–90%, Sigma-Aldrich), n-hexane (97%, Sigma-Aldrich), YbCl₃·6H₂O (99.99%, Sigma-Aldrich), APTES (99%, Sigma-Aldrich) and acetone (99.7%, Beijing Chemical Work) were used as received without further purification.

Copper(I) iodide (CuI, 99.999%, Sigma-Aldrich),
indium acetate In(Ac)₃, 99.99%, Alfa Aesar), 1-dodecanethiol
(DDT, 98%, Sigma-Aldrich), 1-octadecene (ODE, 90%, Acros), zinc stearate
(Zn(St)₂, Acros), mercaptopropionic acid (MPA, Sigma-Aldrich),
1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDC,
ThermoFisher), and NeutrAvidin (ThermoFisher). All solvents were purchased
from VWR International. Methanol, hexane, dimethylformamide, and ethyl
acetate were of pure grade. All of the water used in this study was
ultrapure 18MΩ·cm Millipore water obtained from a Direct-Q
3UV water filtration system.

Carbonyl iron (Fe(CO)₅) was obtained from the Xindingpengfei Technology Development Co., Ltd (Beijing, China). Chloroauric acid (HAuCl₄) and oleic acid (OA) were delivered by Sigma-Aldrich (USA). The 1-octadecene (ODE) was purchased from Acros (Shanghai, China). Tetramethyl ammonium hydroxide (TMAH), silver nitrate, and hydroxylamine hydrochloride were purchased from Adamas-beta (Shanghai, China). Trisodium citrate (TSC) was purchased from Sinopharm Chemical Reagent Co. Ltd (Beijing, China). H₂O₂ was purchased from Chuandong Chemical Co. Ltd (Chongqing, China). Thoil-PEG2K was bought from the Xi’an Ruixi Biological Technology Co., Ltd (Xi’an, China). The Cell Counting Kit-8 (CCK8), Calcein Acetoxymethyl (AM)/Propidium Iodide (PI) Cell Viability Assay Kit, and Penicillin–Streptomycin Solution were purchased from Beyotime Biotechnology (Shanghai, China). Dulbecco’s modified eagle medium (DMEM) and fetal bovine serum (FBS) were obtained from HyClone (Shanghai, China). Phosphate buffer saline (PBS) powder was purchased from Boster Biotechnology (Wuhan, China). All the chemicals were used as delivered and all glassware engaged in synthesis were rinsed by aqua regia and deionized water before use.

For the
synthesis of the CoFeP nanoparticles,^{26 (link)} 2.4 g (10 mmol) of 1-hexadecylamine (HDA, 90%, Acros Organics) was
mixed with 10.0 mL of 1-octadecene (ODE, 90%, ACROS Organics) and
2.6 mL (10 mmol) of TPOP (99%, ACROS Organics) in a 50 mL flask. The
system was degassed, heated to 130 °C, and kept at this temperature
for 1 h to remove low boiling point impurities, moisture, and oxygen.
Then, the mixture was cooled down to 60 °C, and 4 mL of ODE containing
380 mg (1 mmol) Co₂(CO)₈ (95%, ACROS Organics)
and 0.3 mL of (2 mmol) Fe(CO)₅ (Sigma-Aldrich) were added.
First, the temperature was increased to 230 °C, and then, the
mixture was stirred for 30 min. Second, the mixture was heated to
300 °C for 40 min and kept at this temperature for 1 h. Finally,
the system was allowed to cool down to 200 °C by removing the
heating mantle and subsequently cooled rapidly down to room temperature
with a water bath. The product was precipitated using acetone and
centrifuged for 3 min at 7500 rpm. To remove organics, three dispersion
and precipitation cycles using chloroform and acetone were additionally
carried out to obtain a cleaner CoFeP precipitate. To synthesize the
Co₂P nanoparticles used as the reference material, an identical
procedure was followed but without adding the iron precursor.