Measurement of Nanoparticle Concentration Using Quartz Crystal Microgravimetry
Vytautas Reipa, Geoffrey Purdum, Jonghoon Choi
A common issue, encountered in nanoparticle-biological system interaction studies is accurate nanoparticle concentration expression, given the critical importance of the dose-response relationships. We present here the application of quartz crystal microgravimetry (QCM) to accurately measure nanoparticle concentration in a colloidal suspension. Application of a small drop of the nanoparticle suspension in volatile solvent to the crystal surface leaves a dry nanoparticle residue after solvent evaporation and a shift in the crystal resonant frequency is recorded. Instrument was calibrated using a dilution series of Si and Ag nanopowder in methanol, rhodamine B in methanol and ferrocene in cyclohexane. The QCM showed a linear response for nanoparticle concentrations in the range from 5 to 1300 g/ml. Method was used to determine the molar concentrations of size selected octyl-terminated Si nanocrystal samples with diameters in the range from 1.1 to 14.8 nm and calculate size dependent nanocrystal extinction coefficients.
, Purdum, G.
and Choi, J.
Measurement of Nanoparticle Concentration Using Quartz Crystal Microgravimetry, Journal of Physical Chemistry B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=905447
(Accessed February 28, 2024)