组成图示
示意图生成中
传感器类型
电化学生物传感器
检测对象
蔗糖（sucrose）、葡萄糖（glucose）、过氧化氢（H2O2）；样品基质：磷酸盐缓冲液/FIA标准溶液（文中面向甜饮料、食品样品）
检测原理
蔗糖在转化酶（INV）催化下水解为葡萄糖和果糖；变旋酶（MUT）将α-D-葡萄糖转化为β-D-葡萄糖；葡萄糖氧化酶（GOX）氧化β-D-葡萄糖生成葡萄糖酸内酯和过氧化氢（H2O2）。H2O2扩散至普鲁士蓝（PB）膜，在-50 mV下被PB电催化还原为OH-，PB/普鲁士白之间发生可逆电子转移，产生与H2O2浓度成正比的还原电流。由于酶级联将蔗糖转化为H2O2，电流随蔗糖浓度增加而增大。TTS通过弱分子作用稳定PB膜，减少催化循环中OH-导致PB分解，从而维持信号稳定。葡萄糖和H2O2也可直接在PB膜上产生响应。
检测灵敏度
LOD: 蔗糖 4.5 μM、葡萄糖 1.5 μM、H2O2 0.5 μM；线性范围: 蔗糖 4–800 μM、葡萄糖 2–800 μM、H2O2 1–800 μM；斜率: 蔗糖 2.82 nA μM−1、葡萄糖 3.44 nA μM−1、H2O2 9.87 nA μM−1；R^2: 蔗糖 0.9992、葡萄糖 0.9999、H2O2 0.9992
效应效果
100 μM蔗糖下RSD为1.2%（n=15），五电极重现性约8%，分析速率约60个/小时，响应约1分钟/次，工作电位-50 mV；未报告实际样品加标回收率。甘氨酸、丙氨酸、缬氨酸无响应；麦芽糖、果糖、半乳糖无贡献；100 μM葡萄糖相对响应286%，100 μM抗坏血酸误差24%、50 μM为10%。未加TTS时300分钟（195次）损失70%；载体含0.05 M TTS时200分钟（130次）损失<8%但电流降40%；PB活化含TTS时370分钟（240次）损失<14%，4℃储存3天稳定。作者称其检出限、线性范围、分析速率和电位优于多数已报道蔗糖传感器。
传感器的构成
- 基底/工作电极：玻璃碳电极（GC, glassy carbon, 0.066 cm2），作为电子传导基底与换能器。
- 普鲁士蓝修饰层：电沉积普鲁士蓝（PB, Prussian blue, ferriferrocyanide）膜，作为H2O2电催化剂/人工过氧化物酶。
- 稳定剂：四丁基甲苯-4-磺酸盐（TTS, tetrabutylammonium toluene-4-sulfonate），在活化步骤或载体中稳定PB膜，抑制OH-引起分解。
- 识别/酶层：葡萄糖氧化酶（GOX）、变旋酶（MUT）、转化酶（INV）三酶体系，催化蔗糖水解及葡萄糖氧化生成H2O2。
- 交联固定层：牛血清白蛋白（BSA）与戊二醛（GLU）交联，固定三酶并形成稳定膜。
- 信号产物：过氧化氢（H2O2），酶反应最终产物，被PB电催化还原产生安培电流。
中文摘要
本文研究了电沉积普鲁士蓝（PB）膜修饰玻璃碳（GC）电极的操作稳定性，报道在活化步骤中加入四丁基甲苯-4-磺酸盐（TTS）可增强PB膜稳定性。作者构建了用于蔗糖检测的多酶PB生物传感器，证明PB膜可与氧化酶体系偶联。三酶体系包括葡萄糖氧化酶（GOX）、变旋酶（MUT）和转化酶（INV），用戊二醛和牛血清白蛋白（BSA）交联固定在PB修饰GC电极上。PB作为过氧化氢（H2O2）电催化剂，催化酶反应最终产物H2O2的电化学还原。采用流动注射分析（FIA）研究电极对蔗糖、葡萄糖和H2O2的响应。最优固定化混合物为GOX 8 U、MUT 8 U、INV 16 U、0.5%戊二醛和0.5% BSA，总体积5 μL，施加于0.066 cm2电极表面。传感器对蔗糖（4–800 μM）、葡萄糖（2–800 μM）和H2O2（1–800 μM）线性响应，检出限分别为4.5、1.5和0.5 μM，样品通量约60个/小时。在含0.05 M TTS磷酸盐缓冲液中活化PB膜还可提高操作稳定性和储存稳定性。
英文摘要
Stabilisation of electrochemically deposited Prussian blue (PB) films on glassy carbon (GC) electrodes has been investigated and an enhancement in the stability of the PB films is reported if the electrodes are treated with tetrabutylammonium toluene-4-sulfonate (TTS) in the electrochemical activation step following the electrodeposition. A multi-enzyme PB based biosensor for sucrose detection was made in order to demonstrate that PB films can be coupled with an oxidase system. A tri-enzyme system, comprising glucose oxidase, mutarotase and invertase, was crosslinked with glutaraldehyde and bovine albumin serum on the PB modified glassy carbon electrode. The deposited PB operated as an electrocatalyst for electrochemical reduction of hydrogen peroxide, the final product of the enzyme reaction sequence. The electrochemical response was studied using flow injection analysis for the determination of sucrose, glucose and H(2)O(2). The optimal concentrations of the immobilisation mixture was standardised as 8U of glucose oxidase, 8U of mutarotase, 16U of invertase, 0.5% glutaraldehyde (0.025mul) and 0.5% BSA (0.025mg) in a final volume of 5mul applied at the electrode surface (0.066cm(2)). The biosensor exhibited a linear response for sucrose (4-800muM), glucose (2-800muM) and H(2)O(2) (1-800muM) and the detection limit was 4.5, 1.5 and 0.5muM for sucrose, glucose and H(2)O(2), respectively. The sample throughput was ca. 60 samples h(-1). An increase in the operational and storage stability of the sucrose biosensor was also noted when the PB modified electrodes were conditioned in phosphate buffer containing 0.05M TTS during the preparation of the PB films.