柱前衍生毛细管电泳-电致化学发光法测定日用化妆品中的氨甲环酸含量

将氨甲环酸进行N-甲基化衍生反应后,其衍生产物能与联吡啶钌电致化学发光试剂产生强的共发光信号,据此建立了毛细管电泳-电致化学发光法高选择性测定日用化妆品试样中氨甲环酸含量的新方法。实验中发现,添加一种Mg²⁺-海藻糖-SiO^2-₃三元缔合物凝胶至背景电解液中,可极大地改善电泳分离效能。在优化的分析条件下,氨甲环酸和内标物肌氨酸衍生产物的电泳峰可在500 s内达到完全分离,且此两个电泳峰的强度比值与氨甲环酸的初始浓度在10～750μmol/L的范围内呈良好的线性关系(相关系数r²=0.999 3),检出限为3.6μmol/L(S/N=3)。采用内标法对3种市售牙膏膏体和2种面膜护理液中的氨甲环酸进行了定量测定,测得这些试样中氨甲环酸含量的均值分别为4.05、0.24、6.06 mg/g和51.3、7.98 mg/mL,加标回收率在92.5%～104.0%内,结果令人满意。     

非水毛细管电泳-化学发光法测定食品包装材料中酚类环境激素

建立食用包装材料中的双酚A、壬基酚等多种环境激素的非水毛细管电泳-化学发光分析方法.食品包装材料样品浸出物中的双酚A、烷基酚等环境激素经衍生剂DIB-Cl衍生后,经过非水毛细管电泳分离后,分别与过氧草酸酯化学发光反应体系作用,光信号经过光电倍增管接收放大后被检测.以雌二醇(17β-E2)为内标,以相对迁移时间定性,相对发光强度比定量,内标校准曲线法测定样品浸出物中待测物的含量.对影响非水毛细管电泳分离如溶剂组成和比例、电解质浓度、温度、乙酸浓度、电泳电压等条件进行了优化.同时对化学发光体系也进行了优化.4-叔丁基酚、双酚A、4-叔辛基酚、4-壬基酚和四溴双酚 A分别在0.0095～3.0 mg/L, 0.0087～3.0 mg/L, 0.0085～3.0 mg/L, 0.011～3.0 mg/L和0.009～3.0 mg/L范围内线性良好,r＞0.9947.相对迁移时间和相对峰高的RSD分别为0.88%～2.96%和 6.54%～8.57%.加标回收率为86.7%～98.8%.对5种常见的食品包装材料样品进行了测定, 所建立的方法简便、快速、灵敏,适合于食品包装材料中酚类环境激素的检测.     

联吡啶钌电化学发光传感器测定海洛因

利用离子液体为粘合剂制作碳糊电极,采用高分子聚合法,合成包埋有Ru(bpy)2(dcbpy)2+的高分子聚合物,将钌聚合物掺杂于离子液体碳糊电极中,制作电化学发光传感器.结果表明,此传感器具有很好的电化学发光特性,与用石蜡油为粘合剂制作的电化学发光传感器相比,离子液体为粘合剂的电化学发光传感器检测三丙胺的检出限降低1个数量级.海洛因对电化学发光传感器的发光信号有很好的增强作用,基于此建立了高灵敏度检测海洛因的电化学发光分析法,海洛因浓度与电化学发光信号在2.0×10-9～2.0×10-5 mol/L范围内呈良好的线性关系,检出限为8×10-10 mol/L (S/N=3).将电化学发光传感器在5.0×10-9 mol/L海洛因溶液中采用线性循环电位连续扫描60圈,相对标准偏差小于2.2%.本方法用于血清中海洛因的检测,其回收率为94%～101%.     

Tailoring the Properties of Optical Force Probes for Polymer Mechanochemistry

The correlation of mechanical properties of polymer materials with those of their molecular constituents is the foundation for their holistic comprehension and eventually for improved material designs and syntheses. Over the last decade, optical force probes (OFPs) were developed, shedding light on various unique mechanical behaviors of materials. The properties of polymers are diverse, ranging from soft hydrogels to ultra-tough composites, from purely elastic rubbers to viscous colloidal solutions, and from transparent glasses to super black dyed coatings. Only very recently, researchers started to develop tailored OFP solutions that account for such material requirements in energy (both light and force), in time, and in their spatially detectable resolution. We here highlight notable recent examples and identify future challenges in this emergent field.     

甲磺酸帕珠沙星的铽增敏化学发光法测定

甲磺酸帕珠沙星(PM)与Tb3+容易结合形成配合物Tb3+-PM,该配合物通过能量转移反应对KMnO₄-Na₂SO₃这一弱化学发光体系有很强的增敏作用。据此,结合流动注射技术建立了稀土敏化化学发光测定PM的新方法。在最佳试验条件下,PM的浓度与增强的化学发光强度在0.10 ～12 mg·L-1范围内呈良好的线性关系,方法的检出限是0.04 mg·L-1,对1.0 mg·L-1的PM进行11次平行测定,相对标准偏差RSD为1.9%。用于测定注射液和体液中PM的含量,方法简单、快速、灵敏、重现性好,分析结果令人满意。实验对该化学发光体系(KMnO₄-NaSO₃-Tb3+-PM)的发光机理进行了探讨。     

Ultrasound-pretreatment combined with Ti3C2-TiO2-AuNPs enhancing the electrogenerated chemiluminescence of the air-saturated luminol for exosomes detection

It is still a great challenge to develop effective strategies to improve the low electrogenerated chemiluminescence (ECL) of air-saturated luminol. Herein, the synergistic effects of Ti₃C₂-TiO₂-AuNPs nano hybrid and high-intensity focused ultrasound pretreatment (ultrasound-pretreatment) were used to significantly improve the ECL emission of the air-saturated luminol, and the mechanism was proposed. The ultrasound-pretreatment as a green method with the cavitation effect could form O₂^–• and H₂O₂ in situ as an initiator. TiO₂ and Au nanoparticles (AuNPs) were in situ decorated on the Ti₃C₂ surface to form Ti₃C₂-TiO₂-AuNPs, and it was proved as a highly efficient booster which could catalyze and aggregate H₂O₂ to the O₂^–•. The utilization rate of intermediates has been greatly improved. Exosomes as model targets can be sensitively detected by the ECL sensor. The detection limit was 195 particles μL⁻¹. The detection results of exosomes in actual samples are satisfactory. We believe that the ultrasound-pretreatment strategy could be extended to the sensitive detection in the biological sample.