微波辅助法制备氧化铜非酶葡萄糖传感器

采用微波辅助法制备了氧化铜(CuO)材料,其结晶度好,没有杂质,呈现片层堆叠而成的块状结构.以CuO材料修饰玻碳电极作为工作电极(CuO/GCE),饱和甘汞电极作为参比电极,铂丝电极作为对电极,在碱性条件下对葡萄糖溶液进行电化学性能检测.该传感器对520 nM到2.0 mM浓度范围内的葡萄糖溶液实现了优良的检测性能,灵敏度为2491.362μA·cm-2·mM-1,检测限为216 nM(S/N=3),在2 s内就可以完成反应.丙烯酸等物质对传感器的影响可以忽略,具有良好的抗干扰性.     

氨基化树枝状介孔二氧化硅固定葡萄糖氧化酶用于检测葡萄糖

以三乙胺为碱源合成了树枝状介孔二氧化硅纳米粒子（DMSNs），并用3-氨基丙基三乙氧基硅烷（APTES）进行氨基修饰合成了氨基化树枝状介孔二氧化硅纳米粒子（DMSNs-NH₂），将其用于葡萄糖氧化酶（GOD）的固定化研究.采用扫描电子显微镜、透射电子显微镜、红外光谱仪、X射线衍射仪、氮气吸附仪及热重分析仪对固定化GOD（DMSNs-NH₂-GOD）进行了表征，测定了其活性及蛋白载量.结果表明，固定化GOD的直径约为200 nm，形状均一，呈分散的球形微粒；在最佳固定条件下，蛋白载量达225 mg/g，酶活性达215 U/mg；固定化GOD检测葡萄糖的最低检测限为0.0014 mg/mL.利用固定化GOD检测了血清和饮料中的葡萄糖，重复使用36次以上其相对酶活性仍剩余80%.该方法操作方便、准确度高，提高了酶的pH稳定性、热稳定性及重复使用性，降低了检测成本.     

超高效液相色谱-串联质谱法测定卷烟中果糖、葡萄糖、蔗糖、麦芽糖

建立超高效液相色谱–串联质谱法测定卷烟中果糖、葡萄糖、蔗糖、麦芽糖4种水溶性糖的含量。样品用水超声提取,稀释过滤后直接进样,以Acquity BEH Amide色谱柱为分析柱,乙腈和水为流动相,梯度洗脱,采用负离子多反应监测模式分析。果糖和葡萄糖的线性范围为2.5～30μg/mL,蔗糖和麦芽糖的线性范围为0.25～3μg/mL,线性相关系数均大于0.997,方法检出限均为0.03 mg/g。加标样品的平均回收率为93.6%～101.0%,测定结果的相对标准偏差为0.7%～2.9%(n=6)。该方法简便、快速,可用于卷烟样品中果糖、葡萄糖、蔗糖、麦芽糖的测定。     

Lewis酸催化纤维素制乳酸机理研究

Because fossil fuels are continuously depleted, valorization of biomass into valuable liquid products and chemicals is of great significance yet it remains challenging. Among many biomass-derived products, lactic acid is one of the most important renewable monomers for preparing the degradable polymer polylactic acid. The use of raw biomass to produce lactic acid through catalytic conversion is an attractive approach. In this work, the catalytic reaction performance and mechanism of different Lewis acids (Y³⁺, Sc³⁺, and Al³⁺) for the production of lactic acid from cellulose were investigated in detail by isotopic nuclear magnetic resonance (NMR) and mass spectrometry. The production of lactic acid from cellulose includes tandem and competing reactions. The order of catalytic activity for the one-pot conversion of cellulose into lactic acid is as follows: Y³⁺ > Al³⁺ > Sc³⁺. The main tandem reactions involve the hydrolysis of cellulose into glucose, the isomerization of glucose into fructose (the order of catalytic activity, the same below: Y³⁺ > Al³⁺, Y³⁺ > Sc³⁺), the cleavage of fructose via a retro-aldol reaction to glyceraldehyde (GLY) and 1, 3-dihydroxyacetone (DHA) (Sc³⁺ > Y³⁺ > Al³⁺), and the conversion of DHA or GLY to the final product lactic acid (Al³⁺ > Y³⁺ > Sc³⁺). It was found that the process of glucose isomerization to fructose was the key step to the final selectivity of the tandem reaction of cellulose conversion to lactic acid, and it was clarified that the production of lactic acid from DHA underwent a keto-enol (K-E) tautomerization process rather than a classical 1, 2-shift process. First, DHA was transformed into GLY via the isomerization process, then the adjacent hydroxyl group of GLY was removed in the form of water to produce an α, β-unsaturated species. After that, the α, β-unsaturated species underwent K-E tautomerization to generate unsaturated aldehyde-ketone intermediates. Meanwhile, a molecule of water was added to aldehyde-ketone intermediates to obtain a diol product, the hydrogen atom at the methine position was transferred and the lactic acid was finally obtained through the K-E tautomerization process. The in-depth understanding of the reaction mechanism presented in this work will help to design more selective catalysts for cellulose conversion into value-added oxygen-containing small molecule chemicals.      

酶注射式葡萄糖生物传感器建模方法研究

建立了酶注射式生物传感器的机理模型,并通过实验验证模型精确性.用传感器检测1和2 mg/mL葡萄糖溶液得到电压数据,通过数据拟合确定模型参数.将浓度值3 mg/mL带入模型得到预测曲线,再将其与传感器检测数据拟合后曲线进行比较,验证模型精确性.结果表明,参加反应的酶液米氏常数Km为1.97,数学模型与实际传感器工作模型相关系数(R2)为0.998.     

固体超强酸NiO-ZrO_2/SO_4~(2-)的合成及其对葡萄糖电催化氧化的研究

制备了固体超强酸NiO-ZrO2/SO42-,并研究了其对葡萄糖的电催化氧化性能。利用X射线衍射、扫描电镜以及傅里叶变换红外光谱法对其进行表征,同时研究了其对葡萄糖的电催化氧化性能。结果表明:起主要催化作用的为NiO-ZrO2/SO42-中镍的活性物质,而ZrO2/SO42-上的缺电子金属中心加速了反应过程中电子的转移速率,使得NiO-ZrO2/SO42-相比于NiO/SO42-有更低的峰电位,并且表现出更好的稳定性。     

葡萄糖对溶胶凝胶法制备Li1.2Ni0.13Co0.13Mn0.54O2正极材料性能的影响

利用XRD、SEM、EDS、BET、激光粒度、循环伏安、恒流充放电、交流阻抗方法研究了葡萄糖为碳源对溶胶凝胶法制备Li_1.2Ni_0.13Co_0.13Mn_0.54O₂正极材料的结构、形貌以及电化学性能的影响。结果表明:与前驱体中未加入葡萄糖所制备的材料相比,掺葡萄糖后样品颗粒分布相对均匀,粒径变小,D₅₀从11.56减小至9.94μm,比表面积增加近1倍。经0.05C充放电活化后,未掺葡萄糖和掺葡萄糖样品0.2C放电比容量分别为183.4、211.6mAh·g^-1,2C容量分别为其0.2C的62.2%、77.6%。1C循环50次后放电比容量分别为133.3、173.6mAh·g^-1,容量保持率分别为95.1%、100%。掺葡萄糖可降低首次不可逆容量损失,提高材料的倍率性能与循环稳定性,减少电荷传递阻抗、Warburg阻抗以及双电层弥散效应,但不改变材料的晶型结构。     

一种葡萄糖发酵液中乙醇含量的拉曼光谱分析方法

拉曼光谱法可实现样品的快速定量分析,但发酵液等复杂体系中样品的拉曼强度与被测组分含量之间的良好线性关系难以直接得到。本实验中将待测样品与纯被测组分的拉曼光谱均视为向量,并按照向量点积公式计算向量之间的夹角。在被测组分的拉曼光谱特征峰波段,对多组样品在不同光谱区间的向量夹角矩阵和被测组分含量进行偏最小二乘回归,建立定量分析数学模型,从而以光谱向量之间的夹角作为定量指标实现葡萄糖发酵液中乙醇含量的快速测定。选取的主成分数为6时,所建模型校正集和预测集中预测值与实测值的线性相关系数分别为0.9993和0.9933;校正集均方根误差为0.2171。其建模所用样本数量少、对样品无损坏,方法适用于发酵在线监测和过程分析。