TY - JOUR
T1 - Selective Autonomous Molecular Transport and Collection by Hydrogel-Embedded Supramolecular Chemical Gradients
AU - Zhang, Shiyan
AU - Zhang, Chunjie
AU - Chen, Hao
AU - Kieffer, Spencer J.
AU - Neubrech, Frank
AU - Giessen, Harald
AU - Alleyne, Andrew G.
AU - Braun, Paul V.
N1 - Publisher Copyright:
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/12/9
Y1 - 2019/12/9
N2 - Selective transport and concentration of molecules to specified regions on a substrate both enhances the potential to detect such molecules and provides a path to spatially localize such molecules prior to initiation of subsequent chemical reactions. Here, we first embed radially symmetric α-, β-, and γ-cyclodextrin gradients in a hydrogel matrix. Driven by host-guest interactions between the cyclodextrins and the target molecule, we observe these gradients can serve to direct 2D molecular transport. Using xanthene dyes and organophosphates as target molecules, we found the transport metrics, e.g., selectivity, rate, and concentration limits, are strongly dependent on the specific cyclodextrin forming the gradient. In all cases, as the concentrating power of the gradient increased, the rate of target concentration slowed, which we hypothesize is because stronger interactions between the target and the cyclodextrin decrease the rate of target diffusion. The concentration enhancement for the nerve agent simulant 4-methylumbelliferyl phosphate (15.8) is the greatest when the gradient is formed using β-cyclodextrin while directed concentration of cyanomethyl phosphonate, a smaller non-aromatic organophosphate, is observed only for the smaller α-CD. To provide a near real-time read-out of the concentration of the analyte, we used an array of IR resonant metallic nanoantennas tuned to a specific IR absorption band of the analyte to enhance the IR signal generated by the analyte.
AB - Selective transport and concentration of molecules to specified regions on a substrate both enhances the potential to detect such molecules and provides a path to spatially localize such molecules prior to initiation of subsequent chemical reactions. Here, we first embed radially symmetric α-, β-, and γ-cyclodextrin gradients in a hydrogel matrix. Driven by host-guest interactions between the cyclodextrins and the target molecule, we observe these gradients can serve to direct 2D molecular transport. Using xanthene dyes and organophosphates as target molecules, we found the transport metrics, e.g., selectivity, rate, and concentration limits, are strongly dependent on the specific cyclodextrin forming the gradient. In all cases, as the concentrating power of the gradient increased, the rate of target concentration slowed, which we hypothesize is because stronger interactions between the target and the cyclodextrin decrease the rate of target diffusion. The concentration enhancement for the nerve agent simulant 4-methylumbelliferyl phosphate (15.8) is the greatest when the gradient is formed using β-cyclodextrin while directed concentration of cyanomethyl phosphonate, a smaller non-aromatic organophosphate, is observed only for the smaller α-CD. To provide a near real-time read-out of the concentration of the analyte, we used an array of IR resonant metallic nanoantennas tuned to a specific IR absorption band of the analyte to enhance the IR signal generated by the analyte.
KW - chemical gradient
KW - cyclodextrin
KW - molecular transport
KW - selectivity
KW - supramolecular interaction
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U2 - 10.1002/anie.201908647
DO - 10.1002/anie.201908647
M3 - Article
C2 - 31544334
AN - SCOPUS:85074570980
SN - 1433-7851
VL - 58
SP - 18165
EP - 18170
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 50
ER -