ac303591n_si_001.pdf (1.71 MB)
Download fileColorimetric Visualization of Glucose at the Submicromole Level in Serum by a Homogenous Silver Nanoprism–Glucose Oxidase System
journal contribution
posted on 2013-07-02, 00:00 authored by Yunsheng Xia, Jingjing Ye, Kanghui Tan, Jiajing Wang, Guang YangIn this study, we design a homogeneous
system consisting of Ag
nanoprisms and glucose oxidase (GOx) for simple, sensitive, and low-cost
colorimetric sensing of glucose in serum. The unmodified Ag nanoprisms
and GOx are first mixed with each other. Glucose is then added in
the homogeneous mixture. Finally, the nanoplates are etched from triangle
to round by H2O2 produced by the enzymatic oxidation,
which leads to a more than 120 nm blue shift of the surface plasmon
resonance (SPR) absorption band of the Ag nanoplates. This large wavelength
shift can be used not only for visual detection (from blue to mauve)
of glucose by naked eyes but for reliable and convenient glucose quantification
in the range from 2.0 × 10–7 to 1.0 ×
10–4 M. The detection limit is as low as 2.0 ×
10–7 M, because the used Ag nanoprisms possess (1)
highly reactive edges/tips and (2) strongly tip sharpness and aspect
ratio dependent SPR absorption. Owing to ultrahigh sensitivity, only
10–20 μL of serum is enough for a one-time determination.
The proposed glucose sensor has great potential in the applications
of point-of-care diagnostics, especially for third-world countries
where high-tech diagnostics aids are inaccessible to the bulk of the
population.