Growth of Single-walled Carbon Nanotubes on Substrates Using Carbon Monoxide as Carbon Source

The growth of single-walled carbon nanotubes(SWCNTs) on substrates has attracted great interests because of the potential applications in various fields. Carbon monoxide(CO) was used as the carbon source for the growth of SWCNTs on silicon substrates. Random or oriented SWCNTs can be produced by varying the CO flow rate. When the flow rate of CO was as low as 20 sccm(sccm:standard cubic centimeter per minute), dense SWCNT networks with clean surface were produced. When the flow rate was above 50 sccm, vertically aligned SWCNT(VA-SWCNT) arrays were grown. Well-aligned VA-SWCNT arrays were obtained in the temperature range of 650-800℃ and the content of large-diameter(above 1.7 nm) tubes in the array increased with the temperature. The height of the array was affected by the growth temperature, the CO flow rate, and the growth time. These findings indicate CO can be used as an efficient carbon source for the growth of SWCNTs on substrates under low flow rates.     

Donor-Acceptor Typed AIE Luminogens with Near-infrared Emission for Super-resolution Imaging

Aggregation-induced emission(AIE)luminogens(AIEgens)with high brightness in aggregates exhibit great potentials in biological imaging,but these AIEgens are seldom applied in super-resolution biological imaging,especially in the imaging by using the structural illumination microscope(SIM).Based on this consideration,we synthesized the donor-acceptor typed AIEgen of DTPA-BTN,which not only owns high brightness in the near-infrared(NIR)emission region from 600 nm to 1000 nm(photoluminescence quantum yield,PLQYs=11.35%),but also displays excellent photo-stability.In addition,AIE nanoparticles based on 4,7-ditriphenylamine-[1,2,5]-thiadiazolo[3,4-c]pyridine(DTPA-BTN)were also prepared with highly emissive features and excellent biocompatibility.Finally,the developed DTPA-BTN-based AIE nanoparticles were applied in the super-resolution cellular imaging via SIM,where much smaller full width at half-maximum values and high signal to noise ratios were obtained,indicating the superior imaging resolution.The results here imply that highly emissive AIEgens or AIE nanoparticles can be promising imaging agents for super-resolution imaging via SIM.     

A Novel Fluorescent Probe for ATP Detection Based on Synergetic Effect of Aggregation-induced Emission and Counterion Displacement

In this work,a fluorescent probe(TPEBe-I)was developed for adenosine triphosphate(ATP)detection based on the synergetic effect of aggregation-induced emission and counterion displacement.TPEBe-I gave weak emission in aqueous solution due to the heavy-atom effect of counter iodide ion.However,upon the addition of ATP,the new aggregate complex(TPEBe-ATP)was formed between the cationic unit of TPEBe-I and ATP through electrostatic interactions,which not only restricted the intramolecular motion of luminogen but also eliminated the quenching effect of iodide ion.As a result,the fluorescent light-up detection for ATP was successfully achieved.Moreover,TPEBe-I exhibited high selectivity towards ATP and showed a wide linear detection region towards the logarithm of ATP concentration(5—600μmol/L)with a detection limit of 1.0μmol/L,enabling TPEBe-I as a promising probe for ATP quantitative analysis.     

Host-Guest Interactions of Cyclopentanocucurbit[6]uril with Alkyl Imidazolium Hydrochlorides

The host-guest interactions between cyclopentanocucurbit-[6]uril(CyP₆Q[6]) as host and six alkyl imidazolium hydrochloride as guests(g1, g2, g3, g4, g5, and g6) have been studied by various techniques, such as ¹H NMR spectroscopy, isothermal titration calorimetry, mass spectrometry, and single-crystal X-ray diffraction analysis. The experimental results showed that CyP₆Q[6] formed 1:1 inclusion complexes with each of guests g1-g6. The part of the guest entered the cavity of CyP₆Q[6] changes as the alkyl chain increases in length. It can be seen that the length of the alkyl chain plays a key role in determining the mode of host-guest interactions.     

一种计算液接电势的新方法*

依据液接电势达稳态时通过边界层的净电荷为零这一思想,提出了一种计算液接电势的新方法。对于3类液接电势的计算,特别是Lewis-Sargent公式与Henderson方程的推导,思路清晰易懂,避免了过往液接电势计算方法存在的一些问题。本文所提出的方法能够为液接电势相关内容的教学提供借鉴。     

高职扩招背景下食品化学混合式教学设计的重构与实践*

在全国高职院校扩大招生背景下,高职院校的扩招生表现出与统招生不同的学习特点和学习基础,根据扩招生的学情特点和课程标准,对已有混合式教学模式的食品化学课程,从课时设置、课前、课中、课后等几个方面重新进行教学设计和实施。利用线上学习成绩、线下课堂成绩、期末成绩等多维度评价理论课学习效果。结合调查问卷分析学生对混合式教学的评价,表明扩招生的学习自律性和主动性有明显提高,考试不及格率下降,学生对混合式教学的认同度也较高。通过教学重构力图达到教学形式灵活多样,培养标准不降低的目的,并培养学生良好的学习习惯,树立学好课程的信心。     

敞开式电离质谱技术在法医毒物分析中的应用

敞开式电离质谱(Ambient ionization mass spectrometry,AIMS)是指在大气压环境下,无需或只需简单的样品前处理即可对样品中目标物进行分析的质谱技术。AIMS具有简单、快速、无损和适用范围广等优势,被广泛应用于法医毒物分析领域。该文对敞开式电离(Ambient ionization,AI)技术进行了简单概述,将检材分为体内检材和体外检材两大类,综述了AIMS技术在不同类型检材毒物分析中的应用,并对其在法医毒物分析中的发展前景进行了展望。     

非衍生化高效液相色谱-串联质谱法快速检测生物体液中草甘膦、草铵膦及代谢物

建立了一种非衍生化高效液相色谱-串联质谱快速检测生物体液中草甘膦、草铵膦及其代谢物等8种极性农药的方法。8种极性农药经Metrosep A Supp 5阴离子色谱柱(150 mm×4.0 mm,5μm)分离,以纯水-200 mmol/L碳酸氢铵溶液(含0.1%氨水)为流动相进行梯度洗脱,负离子多反应监测(MRM)模式进行检测。实验结果表明,8种极性农药在0.5~50 ng/mL范围内线性关系良好(r²>0.99),检出限(S/N≥3)为0.08~0.3 ng/mL,定量下限(S/N≥10)为0.3~1 ng/mL。方法的基质效应为86.5%~106%,目标化合物的回收率为81.5%~114%,日内相对标准偏差(RSD)为0.30%~2.8%,日间RSD为0.50%~5.3%。该方法无需复杂的衍生化过程,简便快速、灵敏度高、稳定性好,适用于生物体液中8种极性农药的检测。     

SC-ICP-MS法测定金属元素的方法研究

为了使用单细胞电感耦合等离子体质谱(SC-ICP-MS)方法准确测定单个细胞中的铬(Cr)、锰(Mn)、铁(Fe)、铜(Cu)和锌(Zn)等多种内源性金属元素,该文基于动态反应池(DRC)模式对目标分析物的反应气流量和极杆抑制参数q(RPq)进行了优化,并研究了进样速度、细胞密度、驻留时间等因素对SC-ICP-MS检测的影响。分别采用细胞悬液直接进样、使用超声波探头使细胞悬液中的细胞破碎后进样和使用浓硝酸消解细胞后进样的ICP-MS测定结果对SC-ICP-MS定量结果的准确性进行验证分析。实验结果表明,可采用超声波破碎细胞的ICP-MS测定结果评估SC-ICP-MS测定的单细胞内Zn和Cu含量的准确性,采用酸消解细胞的ICP-MS检测结果验证单细胞内Fe和Cr的含量。缺少细胞标准物质时对SC-ICP-MS方法定量结果进行多角度验证是必要的。研究表明,使用SC-ICP-MS法可以较好地进行单细胞元素相关分析。     

基于智能手机检测在食品安全中的应用

近年来,智能手机凭借其轻巧便携、成本低、可个性化定制且使用者无需专业培训等优势,在分析检测中的应用越来越多,并在医疗诊断、环境监测、食品监督等领域展现出广阔的应用前景,是众多学科巧妙结合的典范。该文综述了2015~2020年初基于智能手机的检测技术在食品安全方面的应用,包括对食品添加剂、抗生素、微生物、农残与重金属、生物毒素以及食物新鲜度的检测,为相关研究提供了参考依据,并对这项热门技术在分析检测领域的应用前景进行了展望。