Key University Laboratory on Separation and Analysis of Complex Systems of Liaoning Universities, College of Chemistry and Life Science, Shenyang Normal University, PR of China.
Analyst. 2011 Feb 21;136(4):841-6. doi: 10.1039/c0an00844c. Epub 2010 Dec 13.
A new kind of biosensor for the detection of urea with a high selectivity, sensitivity and wide detection range was designed based on the secretion of carnation petals cells paste covered over a graphite-epoxy composite basic electrode surface. The carnation petal paste from mashed fresh carnation petals was tightly fixed on the basic electrode surface with Teflon thin film to keep it in contact with the electrode surface. Urea in aqueous solution was detected by differential pulse voltammetry based on the oxidation peak current at 0.316 V (vs. SCE) of the secreted species of carnation petal cells during the mashing process, which interacts with urea molecules and results in the decrease of the oxidation peak current. The oxidation peak current decreases linearly with the logarithm of urea concentration in the range of 1.3 × 10(-16)-4.57 × 10(-8) M and 3.4 × 10(-7)-1.3 × 10(-1) M with a detection limit of 7.5 × 10(-16) M. The biosensor was characterized by electrochemistry and fluorescent spectrometry, and applied to the determination of urea in waste water from a river around Shenyang Normal University campus with a recovery of 104.5% (RSD is 5.00%). The presence of larger amounts of ammonium ion and nitrate ion up to the molar ratio of 10(4) do not interfere with the urea detection.
基于康乃馨花瓣细胞分泌物覆盖在石墨-环氧树脂复合基本电极表面的方法，设计了一种用于检测尿素的新型高选择性、高灵敏度、宽检测范围的生物传感器。将新鲜康乃馨花瓣捣碎后得到的康乃馨花瓣糊紧密地固定在基本电极表面的特氟龙薄膜上，以保持与电极表面的接触。在捣碎过程中，康乃馨花瓣细胞分泌的物质与尿素分子相互作用，导致氧化峰电流降低，从而通过差分脉冲伏安法检测水溶液中的尿素。在 1.3×10^(-16)-4.57×10^(-8) M 和 3.4×10^(-7)-1.3×10^(-1) M 范围内，氧化峰电流随尿素浓度的对数呈线性下降，检测限为 7.5×10^(-16) M。该生物传感器通过电化学和荧光光谱进行了表征，并应用于沈阳师范大学校园周围河流废水中尿素的测定，回收率为 104.5%（RSD 为 5.00%）。摩尔比高达 10(4)的大量铵离子和硝酸根离子的存在并不干扰尿素的检测。
