A fluorescence-based glucose biosensor using concanavalin A and dextran encapsulated in a poly(ethylene glycol) hydrogel
A fluorescence-based glucose biosensor using concanavalin A and dextran encapsulated in a poly(ethylene glycol) hydrogel
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DOI：
10.1021/ac990060r
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发表时间：
1999-08-01
影响因子：
7.4
通讯作者：
Coté, GL
中科院分区：
文献类型：
--
作者：
Russell, RJ;Pishko, MV;Coté, GL
描述了一种基于光聚合聚（乙二醇）（PEG）水凝胶的荧光生物传感器，其中掺入荧光素异硫氰酸酯葡聚糖（FITC-葡聚糖）和四甲基罗丹明异硫氰酸酯刀豆球蛋白A（TRITC-Con A），使用PEG-丙酸的α-丙烯酰基、omega-N-羟基琥珀酰亚胺酯化学缀合到水凝胶网络中。在没有葡萄糖的情况下，TRITC-Con A 与 FITC-葡聚糖结合，FITC 荧光通过荧光共振能量转移被猝灭。葡萄糖与 TRITC-Con A 竞争性结合，释放 FITC-葡聚糖，导致 FITC 荧光强度与葡萄糖浓度成正比。在 0.1 M 磷酸盐缓冲盐水 (pH 7.2) 和葡萄糖溶液中对水凝胶球进行了多种 TRITC-Con A/FITC-葡聚糖比例的体外实验。当通过增加葡萄糖浓度释放 FITC-葡聚糖时，根据荧光强度的百分比变化来表征水凝胶。使用 500:5 mu g/mL PEG 的 TRITC-Con A/FITC-葡聚糖质量比获得 0 至 800 mg/dL 之间的最佳荧光变化。荧光响应在高达 600 mg/dL 时呈线性。在较高浓度下，由于大部分 FITC-葡聚糖的置换以及游离 FITC-葡聚糖的浓度猝灭，响应饱和。添加葡萄糖时的动态荧光变化与葡萄糖浓度从 0 到 200 mg/dL 的阶跃变化 10 分钟相似。
A fluorescence biosensor is described that is based on a photopolymerized poly(ethylene glycol) (PEG) hydrogel incorporating fluorescein isothiocyanate dextran (FITC-dextran) and tetramethylrhodamine isothiocyanate concanavalin A (TRITC-Con A) chemically conjugated into the hydrogel network using an alpha-acryloyl, omega-N-hydroxysuccinimidyl ester of PEG-propionic acid. In the absence of glucose, TRITC-Con A binds with FITC-dextran, and the FITC fluorescence is quenched through fluorescence resonance energy transfer. Competitive glucose binding to TRITC-Con A liberates FITC-dextran, resulting in increased FITC fluorescence proportional to the glucose concentration. In vitro experiments of hydrogel spheres in a solution of 0.1 M phosphate-buffered saline (pH 7.2) and glucose were conducted for multiple TRITC-Con A/FITC-dextran ratios. Hydrogels were characterized on the basis of the percent change in fluorescence intensity when FITC-dextran was liberated by increasing glucose concentrations. The optimum fluorescent change between 0 and 800 mg/dL was obtained with a TRITC-Con A/FITC-dextran mass ratio of 500:5 mu g/mL PEG. Fluorescent response was linear up to 600 mg/dL, At higher concentrations, the response saturated due to the displacement of the majority of the FITC-dextran and to concentration quenching by free FITC-dextran, Dynamic fluorescent change upon glucose addition was similar to 10 min for a glucose concentration step change from 0 to 200 mg/dL.