Tetrabromobisphenol
A (TBBPA) is a ubiquitous flame retardant.
A high-throughput immunoassay would allow for monitoring of human
and environmental exposures as a part of risk assessment. Naturally
occurring antibodies in camelids that are devoid of light chain, show
great promise as an efficient tool in monitoring environmental contaminants,
but they have been rarely used for small molecules. An alpaca was
immunized with a TBBPA hapten coupled to thyroglobulin and a variable
domain of heavy chain antibody (VHH) T3–15 highly selective
for TBBPA was isolated from a phage displayed VHH library using heterologous
coating antigens. Compared to the VHHs isolated using homologous antigens,
VHH T3–15 had about a 10-fold improvement in sensitivity in
an immunoassay. This assay, under the optimized conditions of 10%
methanol in the assay buffer (pH 7.4), had an IC50 for
TBBPA of 0.40 ng mL–1 and negligible cross reactivity
(<0.1%) with other tested analogues. After heating the VHH at 90
°C for 90 min about 20% of the affinity for coating antigen T3-BSA
remained. The recoveries of TBBPA from spiked soil and fetal bovine
serum samples ranged from 90.3% to 110.7% by ELISA and agreed well
with a liquid chromatography–tandem mass spectrometry method.
We conclude the many advantages of VHH make them attractive for the
development of immunoassays to small molecules.
Production of chemicals and fuels from renewable cellulosic biomass is important for the creation of a sustainable society, and it critically relies on the development of new and efficient transformation routes starting from cellulose. Here, a chemocatalytic conversion route from cellulosic biomass to methyl glycolate (MG), ethylene glycol (EG), and ethanol (EtOH) is reported. By using a tungsten-based catalyst, cellulose is converted into MG with a yield as high as 57.7 C % in a one-pot reaction in methanol at 240 °C and 1 MPa O , and the obtained MG can be easily separated by distillation. Afterwards, it can be nearly quantitatively converted to EG at 200 °C and to EtOH at 280 °C with a selectivity of 50 % through hydrogenation over a Cu/SiO catalyst. By this approach, the fine chemical MG, the bulk chemical EG, and the fuel additive EtOH can all be efficiently produced from renewable cellulosic materials, thus providing a new pathway towards mitigating the dependence on fossil resources.
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