A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles

The overall goal of this protocol is to demonstrate how upconverting nanoparticles are synthesized and how they can be encapsulated with organic dye molecules to prepare water dispersable nano assemblies. This method can answer questions in nanotechnology and photochemistry fields, such as how you can transfer nanoparticles from organic solvents to aqueous environments, and how to maintain their photo reactivity in water. The main advantage of our unique log and play method is its simplicity and versatility.

The encapsulation procedure can be applied to a range of nanoparticles and organic device combinations. The combination of upconverting nanoparticles and photo active molecules will allow access to a wider range of drugs that require UV light activation. Additionally, this method can provide insight into the energy transfer between luminescent nanoparticles and organic dye molecules.

Generally, nanoparticle encapsulation requires extreme care, especially with respect to the phase transfer step. For instance, the errors in addition sequence or reagent ratios could easily lead to the particle aggregation. Visual demonstration of this method is critical because there are several challenging steps involving the encapsulation technique.

Therefore, it requires precise timing, quantity of materials and temperatures. First place a 250 milliliter heating mantle on a regular stirring plate and plug the mantle onto a thermocouple. Place a 250 milliliter round bottom flask equipped with a magnetic stir bar onto the heating mantle.

With proper clamping, attach an air adapter to the left neck of the round bottom flask and connect this air adapter to a schleck line with plastic tubing. Following this, attach a glass adapter to the right neck of the round bottom flask and fix a thermometer adapter onto the glass adapter. Insert a temperature probe into the flask through the thermometer adapter, and plug this into the thermocouple.

Attach a distillation, head to the middle, neck of the round bottom flask and place a stopper on top of the distillation head. Connect the head to a condenser, followed by a vacuum distillation adapter and a 50 milliliter round bottom flask. Then connect the vacuum distillation adapter to a bubbler through plastic tubing.

Next place, one point 17 grams of atrium acetate 0.439 grams of itum acetate and 0.0727 grams of erbium acetate into the 250 milliliter round Bottom flask, add 30 milliliters of oleic acid and 75 milliliters of essene to the flask. Using a graduated cylinder, connect the flask to the double manifold sch lank line, and turn the corresponding valve to keep the flask connected to the nitrogen line. Turn on the thermocouple and set the temperature to 80 degrees Celsius.

Gradually heating the system to this temperature by setting the thermocouple on the 50 to 500 milliliter setting. After all starting materials are dissolved, remove the heating mantle and allow the reaction to cool to 30 degrees Celsius. When the temperature reaches 30 degrees Celsius, remove the distillation head, switch the air adapter from the left neck to the middle neck and close off the left neck with a stopper.

Then slowly introduced vacuum to the reaction flask by turning the valve on thenk line from the nitrogen line to the vacuum line. When the solution stops bubbling, increase the temperature to 115 degrees Celsius at a speed of five degrees Celsius per minute. After 15 minutes at 115 degrees Celsius, remove the heating mantle and cool the reaction to 50 degrees Celsius.

Afterwards, quickly switch the setup back to the original form by reattaching the distillation head to the middle neck and the air adapter to the left neck. During the cooling process, add point 74 grams of sodium hydroxide, 0.5 grams of ammonium fluoride to a plastic bottle with a cap, and dissolve the reagents in 50 milliliters of methanol by sonication following sonication. Pour the solution into the 250 milliliter round bottom flask and rinse the sides of the flask with five milliliters of methanol.

After allowing the solution to stir at 50 degrees for 30 minutes, increase the temperature to 75 degrees Celsius to distill the methanol during the distillation, empty the collection flask when necessary. After the distillation is finished, heat the reaction to 300 degrees Celsius under nitrogen protection as fast as possible. Once the temperature reaches 300 degrees Celsius, maintain this temperature for one hour.

If needed, cover the setup with aluminum foil to help maintain the temperature. Then remove the heat source, allowing the reaction to cool to room temperature. After cooling to room temperature, split the solution evenly into three 50 milliliter plastic centrifugation tubes, and fill each tube to the 50 milliliter scale using anhydrous ethanol centrifuge, all the tubes at 3, 400 times G for 15 minutes.

After discarding the supra natant, re disperse the upconverting nanoparticle or UCNP pellets in 7.5 milliliters of hexanes, and fill each tube with ethanol to the 50 milliliter scale. Following centrifugation at 3, 400 times G for 15 minutes, discard the snat and re disperse the solid U cnps in 30 milliliters of chloroform in the tube. Then transfer the solution into a glass sation vial for further use.

At this point, 25 milligrams of polystyrene, Ultima and hydride or PSMA in three milliliters of chloroform. In a scintillation vial equipped with a magnetic stir bar, then add 250 microliters of the UCNP chloroform stock solution to the vial. Stir the solution at room temperature for two hours.

Next, dissolve 160 milligrams of polyetheramine 2070. In one milliliter of chloroform, add the solution to the scintillation vial in one portion using a pipette. After stirring the solution overnight at room temperature, dispense the appropriate quantity of organic dye molecules into the scintillation vial in one portion.

Then stir the resulting solution for one hour. Next, remove the chloroform under reduced pressure using a rotary evaporator. When finished, add three milliliters of a 0.001 molar aqueous sodium hydroxide solution to the scintillation vial, and sonicate the vial until a milky suspension is formed.

After placing the vial back on the rotary evaporator, carefully remove the remaining chloroform until the suspension is turned to a clear solution. Following this, transfer the solution from the scintillation vial to two 1.5 milliliter conical centrifugation tubes, centrifuge the solutions at 20, 600 times G for 25 minutes. After discarding the supernatant, add 1.5 milliliters of deionized water to each tube and sonicate the tubes to re disperse the pellets in the water following centrifugation under the same conditions as before.

Discard the supernatant and add 1.5 milliliters of deionized water to each tube. Once the pellets have been re dispersed in the water by sunation filter each aqueous nanoparticle dispersion sample through a 0.2 micron syringe filter to obtain the final samples for further testing. Upon irradiation with a near infrared 980 nanometer laser green emission is produced from the TPP UCNP sample, which is assigned to the emission from the Erbium doped sodium atrium.

Fluoride upconverting nanoparticles upon irradiation of the mixed D-A-E-U-N-C-P sample with UV light, the colorless ring opened isomer is converted to the colored ring. Closed isomer and exposure to visible light triggers the reverse process. As is typical for diara Athene, none of the ring opened isomers absorb in the visible region of the electromagnetic spectrum.

Irradiation of the ring opened isomers with 365 nanometer light produces their ring closed counterparts. Selective photo chrom was observed because the two chromophores and encapsulated within the polymer shell of D-A-E-U-C-N-P have well separated absorption bands, which supports the conclusion that the amphiphilic polymer shell helps to retain the efficiency of photo reactions in water. Since the emission bands from the U CMPs overlap with the absorption bands of the ring closed isomers, the quenching of the U CMPs emission is achieved through an energy transfer process.

When the sample is irradiated with visible light of a wavelength greater than 650 nanometers, only the ring closed, isomers returned to the ring, opened isomer, and the red emission is regenerated. While the green emission is still quenched to some extent, Once mastered, this technique can be done in 48 hours if performed properly. While attempting this procedure, it is important to remember to clean all glassware thoroughly to ensure successful synthesis of the nanoparticles after its development.

This technique paved the way for researchers in the field of bioimaging. It allowed them to create and explore how upconverting nanoparticles with tunable fluorescence can be used to improve image quality. After watching this video, you should have a good understanding of how to synthesize these upconverting nanoparticles and make nano assemblies containing those particles and organic dye molecules.

Do not forget that working with lanthanides, organic solvents, aqueous spaces, and elevated temperatures can be extremely hazardous. Precautions, such as wearing personal protective equipment should always be taken while performing this procedure.