Quantitative characterization of the colloidal stability of metallic nanoparticles using UV-vis absorbance spectroscopy.
Plasmonic nanoparticles are used in a wide variety of applications over a broad array of fields including medicine, energy, and environmental chemistry. The continued successful development of this material class requires the accurate characterization of nanoparticle stability for a variety of solution-based conditions. Although many characterization methods exists, there is an absence of a unified, quantitative means for assessing the colloidal stability of plasmonic nanoparticles. We present the particle instability parameter (PIP) as a robust, quantitative, and generalizable characterization technique based on UV-vis absorbance spectroscopy to characterize colloidal instability. We validate PIP performance with both traditional and alternative characterization methods by measuring gold nanorod instability in response to different salt (NaCl) concentrations. We further measure gold nanorod stability as a function of solution pH, salt, and buffer (type and concentration), nanoparticle concentration, and concentration of free surfactant. Finally, these results are contextualized within the literature on gold nanorod stability to establish a standardized methodology for colloidal instability assessment.
Department of Mechanical Engineering, University of California, Santa Barabara, Building II, Room 2355, Santa Barbara, California 93106-5070, United States.
Tyler R
TR
Ray
Department of Mechanical Engineering, University of California, Santa Barabara, Building II, Room 2355, Santa Barbara, California 93106-5070, United States.
Bethany
B
Lettiere
Department of Mechanical Engineering, University of California, Santa Barabara, Building II, Room 2355, Santa Barbara, California 93106-5070, United States.
Joseph
J
de Rutte
Department of Mechanical Engineering, University of California, Santa Barabara, Building II, Room 2355, Santa Barbara, California 93106-5070, United States.
Sumita
S
Pennathur
D002021:Buffers; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D003102:Colloids; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013501:Surface-Active Agents / Q000737:chemistry
D002021:Buffers; D002593:Cetrimonium Compounds; D003102:Colloids; D013501:Surface-Active Agents; D012965:Sodium Chloride; D000077286:Cetrimonium