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Enhanced Stability of Enzyme Immobilized in Rationally Designed Amphiphilic Aerogel and Its Application for Sensitive Glucose Detection
journal contribution
posted on 2020-03-12, 19:40 authored by Chong-Bo Ma, Yu Zhang, Qiong Liu, Yan Du, Erkang WangNatural
enzyme complex with the subunits cooperating with each
other could catalyze cascade reactions in biological system but, just
like the limitation of free-floating natural enzymes, usually suffer
from deactivation in harsh environment such as high temperature. In
this study, a purpose-driven design of amphiphilic aerogel working
as the enzymes-immobilization substrate to form the multienzyme complex
(MEC) was demonstrated. The aerogel was synthesized only by a single
polymer poly(vinyl alcohol) (PVA) as well as a surface modulator maleic
acid (MA), the incorporation of which tunes the surface wettability.
The usage of the amphiphilic aerogel may do favor for multienzyme
immobilization, conserving the enzyme conformation as well as stabilizing
the enzymes in high temperature. As a typical example, glucose oxidase
and hemin were firmly coimmobilized in the aerogel matrix and actively
catalyze the cascade reactions of (i) glucose to gluconic acid and
(ii) 3,3,5,5-tetramethylbenzidine (TMB) to its oxidized state. The
enzymes could resist the degradation under high temperature (70–100
°C) which is witnessed by the rate of decrease in activity was
progressively slackened. Taking the advantage of the chromogenic reaction
of TMB, a glucose sensor based on aerogel-enzyme composite for glucose
detection in whole blood and sweat was established, exhibiting reliable
results and satisfactory recovery. The modified aerogel could also
withstand multiple physical deformation meantime maintaining good
adsorption capacity as well as catalytic performance. The enzymes-loading
aerogel model may hopefully contribute to composing sensors based
on other analytes.