title: Colorimetric detection of catalytic reactivity of nanoparticles in complex matrices.
abstract: There is a need for new methodologies to quickly assess the presence and reactivity of nanoparticles (NPs) in commercial, environmental, and biological samples since current detection techniques require expensive and complex analytical instrumentation. Here, we investigate a simple and portable colorimetric detection assay that assesses the surface reactivity of NPs, which can be used to detect the presence of NPs, in complex matrices (e.g., environmental waters, serum, urine, and in dissolved organic matter) at as low as part per billion (ppb) or ng/mL concentration levels. Surface redox reactivity is a key emerging property related to potential toxicity of NPs with living cells, and is used in our assays as a key surrogate for the presence of NPs and a first tier analytical strategy toward assessing NP exposures. We detect a wide range of metal (e.g., Ag and Au) and oxide (e.g., CeO2, SiO2, VO2) NPs with a diameter range of 5 to 400 nm and multiple capping agents (tannic acid (TA), polyvinylpyrrolidone (PVP), branched polyethylenimine (BPEI), polyethylene glycol (PEG)). This method is sufficiently sensitive (ppb levels) to measure concentrations typically used in toxicological studies, and uses inexpensive, commercially available reagents.
authors: †Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States.
authors: Charlie
authors: C
authors: Corredor
authors: †Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States.
authors: Mark D
authors: MD
authors: Borysiak
authors: ‡Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195, United States.
authors: Jay
authors: J
authors: Wolfer
authors: §School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85287, United States.
authors: Paul
authors: P
authors: Westerhoff
authors: †Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States.|‡Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195, United States.
authors: Jonathan D
authors: JD
authors: Posner
mesh_terms: D002384:Catalysis; D003124:Colorimetry / Q000379:methods*; D004396:Coloring Agents / Q000737:chemistry; D004583:Electrons; D004777:Environment; D006046:Gold / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D011205:Povidone / Q000737:chemistry; D013634:Tannins / Q000737:chemistry; D014867:Water
chemical_list: D004396:Coloring Agents; D013634:Tannins; D014867:Water; D011092:Polyethylene Glycols; D006046:Gold; D011205:Povidone; D008751:Methylene Blue