Responsive Au@polymer hybrid microgels for the simultaneous modulation and monitoring of Au-catalyzed chemical reaction

National Science Foundation of China [21274118, 91227120, 20923004]; Program for New Century Excellent Talents in University of Ministry of Education of China [NCET-13-0506]; Natural Science Foundation for Distinguished Young Scholars of Fujian Province; Program for New Century Excellent Talents in Fujian Province University; Fundamental Research Funds for the Central Universities [2012121016]; National Fund for Fostering Talents of Basic Science [J1310024]The simultaneous modulation and monitoring of catalysis is possible when using metal@polymer hybrid microgels by rational design. Such hybrid microgels are made of Au nanoparticles covered with a temperature and pH dual-responsive copolymer gel shell of poly(N-isopropylacrylamide-co-allylamine). The Au nanoparticle cores can act as catalysts in a model electron-transfer reaction between hexacyanoferrate(ii) and borohydride ions. The introduction of a smart polymer gel shell onto the Au nanoparticles can not only allow modulation of the catalysis of the Au nanoparticle cores through varying the solution temperature, but also allow label-free in situ localized surface plasmon resonance (LSPR) monitoring of the kinetics and thermodynamics of the catalyzed chemical reaction. Unlike conventional spectroscopic methods that only reflect the overall information occurring in the reaction system, the label-free in situ LSPR monitoring gives local information occurring on the catalytic surface and therefore has the potential to advance our understanding of the catalyzed chemical reaction