I have prepared the pH sensitive nanoparticles and want to check their pH sensitivity.
For pH sensitivity first chose appropriate buffer like HEPEs and vary pH by using acid/base. Then measure its zeta potential for stability. By using stable nanoaprticle solution at particular pH you can measure their sensitivity towards different analytes.
For pH sensitivity first chose appropriate buffer like HEPEs and vary pH by using acid/base. Then measure its zeta potential for stability. By using stable nanoaprticle solution at particular pH you can measure their sensitivity towards different analytes.
As Ravi has already stated....
you can try the pH range from pH2 to pH 10 and study the stability pattern of your samples and accordingly you can diagnose the stability of your nanoparticles at a particular pH
you can also have a rough idea from your synthesis method if it come under the category of some physical mode of synthesis...but it will just give you a rough idea any which way you have to confirm it with Zeta Potential only........
As the others already said, you can use the zeta potential of the dispersion in order to estimate the stability of your particles in a broad pH range.
I will try to explain the possibilities by starting with a brief description of what is zeta potential and how is it actually measured. The latter may be important for you, depending on the type, concentration and color of your samples.
The effective charge of particles in a specific solution is a result of the interaction of the particle’s surface charge and the ions in the solution. The type and concentrations of the constituents determine this charge and it is a measure of the electrostatic stability of the dispersion (also called zeta potential).
Stability can thus be influenced through changing pH-values, ion concentration or type, employing additives, polyelectrolytes or cross-linking agents.
The effective charge or zeta potential of particles is classically measured as the speed at which they move in an external electric field (electrophoresis) by applying a direct current. In this case, the particles start moving towards one of the electrodes. The actual measured parameter is their dynamic mobility. Limitations of the classic approach are: high particle concentrations (multiple scattering phenomena), opaque or colored dispersions (light absorption), stirring is forbidden (directed motion). The contrast between the solvent and the solute depends on the refractive index difference. Directed motion influences the speed at which the particles move in the external electric field and thus falsifies the results of the measurement. Multiple scattering and light absorption result in the detection of either more or less light than what is expected and thus the results do not correspond well with the real system.
If an alternating current is used to force the charged particles to move. In this case, they oscillate with the frequency of the external electric field. The oscillation of matter at frequencies of 200 KHz to 2 MHz produces sound waves with a net impulse transfer as long as there is sufficient density difference between the particles and the surrounding solvent (contrast). The amplitude of this wave or the electrokinetic sonic amplitude (ESA) is proportional through proven theory to the dynamic mobility and thus to the zeta potential of the particles in the dispersion.
The ESA technology allows for stirring, titration and addition of further components, on-line and dip-in measurements of the zeta potential. Furthermore, concentrated, colored, turbid, viscous and even crème like samples can be studied with ease. One limitation is that the concentration of the particles should be at least 0,5 % and there should be a density difference of at least 0,2 g/cm3.
Using a titrator that works in conjunction with the zeta potential device is the unit combination that will reveal the pH stability of your particles in dispersion. Such measurement will provide you with information about the sign and the strength of the particle's charge at different pH values.
thank u for above all answers i am using pH sensitive polymer at pH 7.4 how i can ensure that nanoparticles having pH sensitivity
If you are loading the the drug into the polymer, perform the drug release study the in different pH media like pH 1.2, 3.5, 4.5. 6.8 and 7.4( ref . Gugulothu et al, Curcumin -celecoxib nanopartilces paper paper, i have uploaded in my profile.). Also check the particle size , zeta potential in different time intervals.
how we conclude pH sensitivity of nanoparticles by measuring zeta potential
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