纳米TiO2管电化学生物传感器用于测定水体中微囊藻毒素

制作了辣根过氧化物酶和溶胶-凝胶结合Nafion-TiO2修饰石墨电化学传感器,用示差脉冲伏安法研究了该修饰电极的电化学性质,并优化了微囊藻毒素-LR(MC-LR)的测定条件.结果表明,在pH=6.5柠檬酸-NaOH-HCl缓冲溶液中,采用该修饰电极示差脉冲伏安法测定MC-LR,质量浓度在10-5～1μg/L范围内呈良好的线性关系,脉冲伏安法测定微囊藻毒素线性方程为100Δi=0.142 2logC+0.799 7,相关系数为0.995 0,最低检测限达10-6μg/L.电极的重现性及稳定性较好,连续测定10次,相对标准偏差为2.5%;4℃下储存28d后示差脉冲信号无明显变化;应用于饮用水中MC-LR的测定,样品的回收率为99.3%～102.9%.该传感器灵敏度高、稳定性好.     

同时检测淡水鱼加工中土霉素和微囊藻毒素(MC-LR)残留量

目的:土霉素是限制我国淡水鱼深加工产品出口的关键抗生素之一;此外,由于水污染加重,淡水鱼中藻毒素残留问题也很严重。研究和开发同时快速检测技术已成为当前急需解决的问题。方法:鲫鱼鱼肉进行不同前处理,利用高效液相色谱测定毒素残留量。结果:土霉素和微囊藻毒素的最低检测限分别为0.1μg/kg、5ng/L。质量浓度范围0.1⁵.0μg/mL的土霉素、微囊藻毒素标准品制备标准曲线,线性关系较好,相关系数分别为0.995、0.998。精密度分别为1.82%、1.68%;回收率范围分别88.1%5.0μg/mL的土霉素、微囊藻毒素标准品制备标准曲线,线性关系较好,相关系数分别为0.995、0.998。精密度分别为1.82%、1.68%;回收率范围分别88.1%¹02.8%、90.6%102.8%、90.6%¹05%。结论:对比酶联免疫反应试剂盒的检测,2种方法结果没有太大差别。     

超高效液相色谱-串联质谱法同时测定水中的呋喃丹、莠去津和微囊藻毒素

目的建立同时测定水中的呋喃丹、莠去津和微囊藻毒素-LR的超高效液相色谱-串联质谱方法。方法样品直接过0.22μm的水系滤膜,以0.1%甲酸水溶液(A)和乙腈(B)为流动相经BEH C18柱(100 mm×2.1 mm,1.7μm)梯度洗脱分离,串联四极杆质谱在电喷雾正离子(electrospray ionization,ESI+)模式下同时测定呋喃丹、莠去津和微囊藻毒素-LR的含量。结果呋喃丹、莠去津和微囊藻毒素-LR在0.5~50 ng/m L范围内线性良好,r≥0.999,平均加标回收率90.2%~99.5%,精密度为2.1%~4.5%。结论本方法操作简单、灵敏度高、线性范围宽、结果准确可靠,可用于水中的呋喃丹、莠去津和微囊藻毒素-LR的同时测定。     

Effects of cerium on growth and physiological characteristics of Anabaena flosaquae

In the present study, the effects of cerium (Ce) on the growth and physiological changes were investigated in the cyanobacterium Anabaena flosaquae (A. flosaquae) during a 17-day period. The results showed that the content of chlorophyll a (chl-a) and activity of anti-oxidase (e.g. superoxide dismutase, peroxidase, and catalase) increased with Ce3+ concentration in the range of 0.05 to 0.1 mg/L and the growth of A. flosaquae was stimulated. While at around 5 mg/L, the content of malondiadehyde (MDA) increased significantly but the activ-ity of antioxidase reduced, which resulted in the ruin of antioxidant defense system. Compared to the control (Ce3+-free), the population size of live cells declined significantly. Microcystin-LR (MC-LR), the most common and toxic cyanotoxins produced by A. flosaquae, was de-tected and the highest content of MC-LR was observed in 10 mg/L Ce3+ treatment. These results implied that the aqueous environment might suffer a more negative ecological impact when exposed to relatively low Ce3+ concentrations (<0.1 mg/L).)     

Effects of Microcystin-LR Exposure on Spermiogenesis in Nematode Caenorhabditis elegans

Little is known about the effect on spermiogenesis induced by microcystin-leucine arginine (MC-LR), even though such data are very important to better elucidate reproductive health. In the current work, with the aid of nematode Caenorhabditis elegans (C. elegans) as an animal model, we investigated the defects on spermiogenesis induced by MC-LR. Our results showed that MC-LR exposure induced sperm morphology abnormality and caused severe defects of sperm activation, trans-activation, sperm behavior and competition. Additionally, the expression levels of spe-15 were significantly decreased in C. elegans exposed to MC-LR lower than 16.0 μg/L, while the expression levels of spe-10 and fer-1 could be significantly lowered in C. elegans even exposed to 1.0 μg/L of MC-LR. Therefore, the present study reveals that MC-LR can induce adverse effects on spermiogenesis, and those defects of sperm functions may be induced by the decreases of spe-10, spe-15 and fer-1 gene expressions in C. elegans.     

微囊藻毒素-LR的分离纯化

微囊藻毒素-LR （MC-LR）是淡水蓝藻产生的毒性极强的毒素,通过接触、饮用等途径对人体健康造成极大威胁。通过对产微囊藻毒素-LR的铜绿微囊藻进行培养,采用超声波破碎、溶剂萃取法进行萃取,并经高效液相色谱法进行纯化,最终获得微囊藻毒素-LR纯品,为微囊藻毒素-LR的进一步研究奠定基础。     

A MINIATURE SURFACE PLASMON RESONANCE BIOANALYTICAL SYSTEM FOR FIELD DETECTION OF MICROCYSTIN-LR IN SURFACE WATER

A miniature surface plasmon resonance (SPR)–based immunoassay system for analyzing microcystin-LR (MC-LR) in surface water has been developed. A Spreeta biosensor was adopted in the SPR flow injection analysis (FIA) system. An optional biofilm immobilization method was exploited using covalent-coupling between a bioconjugate of microcystin-LR and bovine serum albumin [(MC-LR)-BSA] and the golden surface. An acceptable relative standard deviation of repeatability, 1.29% (n = 20), was achieved. An analysis of the calibration curve showed that this method has a detection limit of 0.55 ng/mL, a half-maximal inhibitory concentration (IC₅₀) of 5.6 ng/mL, and a quantitative range of 1.56–25.00 ng/mL. The recovery from water samples containing varying concentrations of MC-LR ranged from 90% to 112%. After samples of tap water and pool water were assayed, it was concluded that tap water did not contain a measurable amount of the analyte, whereas pool water contained 2.39 ng/mL. Compared to other methods of analysis, SPR immunoassay has the advantage of being label-free, rapid, and cost-effective and can easily detect levels of MC-LR within the World Health Organization (WHO) drinking water guidelines. The SPR FIA system with reusable biosensor is compact and convenient for instant in situ determination of MC-LR levels in environmental water.     

基于核酸适配体的微囊藻毒素LR纳米金生物传感检测方法的建立及其识别机制研究

目的建立微囊藻毒素-LR(microcystin-LR, MC-LR)的纳米金生物传感比色检测法,并探究核酸适配体截短后对此方法检测效果的影响。方法采用柠檬酸钠还原法制备纳米金,通过优化盐浓度、适配体浓度、适配体与MC-LR的反应时间,建立了MC-LR的纳米金生物传感比色检测法。然后,采用组合型核酸适配体截短策略,探究了截短后的核酸适配体对比色法检测MC-LR的影响。结果 NaCl浓度为0.9mol/L,适配体浓度为0.4μmol/L, MC-LR与核酸适配体的反应时间为10 min时为其最适检测条件。在最适条件下,该方法的目测最低检测限为0.4μg/mL,仪器读数最低检测限为(1.05±0.002)ng/mL,线性检测范围为0～1.1μg/m L。探究得出核酸适配体截短后会影响其对MC-LR的识别活性。结论该方法简单、易行,线性检测范围宽,为小分子危害物核酸适配体的快速鉴定奠定了理论基础,同时,对截短核酸适配体与小分子危害物的识别活性研究提供了技术支撑。     

液相色谱-三重四级杆串联质谱法快速检测水中微囊藻毒素-LR

目的 建立液相色谱-三重四级杆串联质谱法快速检测水中微囊藻毒素-LR (microcystin-LR, MC-LR)含量的分析方法。方法 将水样直接过0.45 μm滤膜, 经色谱柱XDB-C18, 以乙腈和0.1%的甲酸水为流动相, 梯度洗脱, 柱温25 ℃, 流速0.2 mL/min, 外标法定量。结果 在微囊藻毒素-LR浓度为0.2~20 μg/L的范围内呈良好的线性关系(r2=0.999)。平均加标回收率在96.8%~101.7%, 相对标准偏差为0.21%~1.80%。检出限为0.2 μg/L, 定量限为0.5 μg/L。结论 该方法快速, 准确, 适用于水样中MC-LR的检测, 为相关检测机构的监测工作提供参考。