Nanomaterials such as nanosilver (AgNP) can be released into the aquatic environment through production, usage, and disposal. Sensitive and cost-effective methods are needed to monitor AgNPs in the environment. This work is hampered by a lack of sensitive methods to detect nanomaterials in environmental matrixes. The present study focused on the development, calibration and application of a passive sampling technique for detecting AgNPs in aquatic matrixes. A Carbon Nanotube Integrative Sampler (CNIS) was developed using multi-walled carbon nanotubes (CNTs) as the sorbent for accumulating AgNPs and other Ag species from water. Sampling rates were determined in the laboratory for different sampler configurations and in different aquatic matrixes. The sampler was field tested at the Experimental Lakes Area, Canada, in lake water dosed with AgNPs. For a configuration of the CNIS consisting of CNTs bound to carbon fiber (i.e. CNT veil) placed in Chemcatcher® housing, the time weighted average (TWA) concentrations of silver estimated from deployments of the sampler in lake mesocosms dosed with AgNPs were similar to the measured concentrations of "colloidal silver" (i.e. <0.22μm in size) in the water column. For a configuration of CNIS consisting of CNTs in loose powder form placed in a custom made housing that were deployed in a whole lake dosed with AgNPs, the estimated TWA concentrations of "CNIS-labile Ag" were similar to the concentrations of total silver measured in the epilimnion of the lake. However, sampling rates for the CNIS in various matrixes are relatively low (i.e. 1-20mL/day), so deployment periods of several weeks are required to detect AgNPs at environmentally relevant concentrations, which can allow biofilms to develop on the sampler and could affect the sampling rates. With further development, this novel sampler may provide a simple and sensitive method for screening for the presence of AgNPs in surface waters.
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http://dx.doi.org/10.1016/j.scitotenv.2016.06.095 | DOI Listing |
Acc Chem Res
January 2025
The Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, United States.
ConspectusIn the search for efficient and selective electrocatalysts capable of converting greenhouse gases to value-added products, enzymes found in naturally existing bacteria provide the basis for most approaches toward electrocatalyst design. Ni,Fe-carbon monoxide dehydrogenase (Ni,Fe-CODH) is one such enzyme, with a nickel-iron-sulfur cluster named the C-cluster, where CO binds and is converted to CO at high rates near the thermodynamic potential. In this Account, we divide the enzyme's catalytic contributions into three categories based on location and function.
View Article and Find Full Text PDFbioRxiv
January 2025
Chemical and Biological Engineering - Iowa State University, 618 Bissell Rd, Ames, IA 50011.
Proteins can be rapidly prototyped with cell-free expression (CFE) but in most cases there is a lack of probes or assays to measure their function directly in the cell lysate, thereby limiting the throughput of these screens. Increased throughput is needed to build standardized, sequence to function data sets to feed machine learning guided protein optimization. Herein, we describe the use of fluorescent single-walled carbon nanotubes (SWCNT) as effective probes for measuring protease activity directly in cell-free lysate.
View Article and Find Full Text PDFPNAS Nexus
January 2025
Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA.
DNA has found increasing applications in molecular engineering, yet its chiral property has rarely been utilized. Here, we report a mirror-image experiment using naturally occurring D-DNA and its enantiomer L-DNA to sort a chiral mixture of single-wall carbon nanotubes (SWCNTs). We find that parity conservation leads to a robust experimental outcome: changing DNA chirality results in handedness inversion of the purified nanotube.
View Article and Find Full Text PDFInd Eng Chem Res
January 2025
Department of Chemistry, Physics, and Materials Science, Fayetteville State University, Fayetteville, North Carolina 28301, United States.
An efficient Suzuki cross-coupling reaction under continuous flow conditions was developed utilizing an immobilized solid supported catalyst consisting of bimetallic nickel-palladium nanoparticles (Ni-Pd/MWCNTs). In this process, the reactants can be continuously pumped into a catalyst bed at a high flow rate of 0.6 mL/min and the temperature of 130 °C while the Suzuki products are recovered in high steady-state yields for prolonged continuous processing.
View Article and Find Full Text PDFACS Omega
January 2025
School of Chemical Engineering, Vellore Institute of Technology, Vellore, Tamil Nadu 632014, India.
This work explores the enhancement of EMI shielding efficiency of polyurethane (PU) foam by loading multiwall carbon nanotube (MWCNTs)-decorated hollow glass microspheres (HGMs). MWCNT was coated onto the HGM surface by a simple solution casting technique. The coated HGM particles were loaded in PU foams, resulting in an even dispersion of MWCNT in the foam struts, thereby forming an interconnected conductive network in the polymer matrix.
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