银纳米枝的合成及表面增强拉曼效应

利用硝酸银与铜之间发生置换反应原理, 在铜箔上得到了有序的银纳米枝结构, 用十二烷基磺酸钠(SDS)为表面活性剂, 通过调控前驱体硝酸银的浓度, 可在铜箔上得到不同密度的银纳米枝. 表面拉曼增强实验结果表明, 当分别以对巯基苯胺(4-ATP)、腺嘌呤和罗丹明G6为探针分子时, 有序的银纳米枝结构比无序的银纳米粒子具有更好的拉曼增强活性; 且随银纳米枝密度的增加, 表面拉曼增强活性有所提高. 该有序的银纳米枝结构是较好的表面增强拉曼(SERS)活性基底, 在有机分子和生物分子的SERS检测方面将具有一定的应用前景.     

A highly fluorescent adenine derivative and its interaction with iron ions

In this paper, an adenine-derived fluorescent chromophore (HCC-APA) was synthesized to detect its interaction with iron ions. The results showed that a large stokes shift (υ = 10981.5 cm^?1) fluorescence of the HCC-APA was appeared. The fluorescence quantum yields of HCC-APA in DMF and THF were 3.49% and 17.54%, respectively, demonstrating its higher fluorescence performance than unmodified adenine. Besides, the fluorescence quenching of HCC-APA with iron ions was further detected. Fluorescence titration experiments confirmed that the detection limit of HCC-APA for Fe³⁺ was 3.69 μM. The interaction between iron ions and HCC-APA was investigated by continuous variable method, indicating that the binding ratio is 1:1. And the interaction site was deeply explored by ¹H NMR and molecular simulation.     

NAD类似物吸附电极的循环伏安研究

光合作用中主要的氧化还原辅酶是ＮＡＤＰ ／ＮＡＤＰＨ ,呼吸作用中主要的氧化还原辅酶是ＮＡＤ ／ＮＡＤＨ．研究这两个辅酶 ,对于更好地了解生命现象并且模仿生物体设计高效清洁的能源具有重要意义．这两个辅酶的活性基团都是吡啶氮上烃基取代的烟酰胺环．为了避开ＮＡＤ分子本身复杂的化学结构 ,人们设计了许多简单分子来作为ＮＡＤ的类似物．有代表性的ＮＡＤ类似物有甲基烟酰胺［１］,苄基烟酰胺［２］等．但人们在研究中发现 ,在ＮＡＤ类似物的还原过程中 ,存在着如下的一个自由基的二聚反应 :而在生物体中 ,由于每个氧化还原酶中…     

几种促进剂存在下细胞色素C电子迁移过程的研究

报道了应用近年来发展的薄层光谱电化学技术,对几种促进剂（４,４＇－二硫基联吡啶、腺嘌呤、Ｌ－半胱氨酸）存在下细胞色素Ｃ电子迁移过程进行了探讨。     

A 3D Adenine-based Cd-MOF: Synthesis,Structure and Photoluminescent Sensing for an Aromatic Azo Compound

A new Cd-MOF containing the nucleobase adenine and multicarboxylates, Cd₂(tdc)₂(1H-ade)₂(H₂O) (H₂tdc = 2,5-thiophene carboxylic acid, 1H-ade = adenine), was synthesized successfully under hydrothermal condition and characterized by single-crystal X-ray diffraction, infrared spectrum, thermogravimetric analysis and photoluminescence. The two crystallographically unsymmetrical Cd atoms are bridged by 2,5-tdc ligands with (κ¹-κ¹)-(κ¹)-μ₃ and (κ¹–κ¹)–μ₂ modes into two dimensional extended layers, which are further pillared with the neutral ade molecules to form a 3D frameworks stabilized by extensive π ··· π interactions between imidazole-, pyrimidine- and thiophene-rings. Inspection of the structure reveals that the architecture can be simplified as a 3,4,5- connected networks with a Schläfli symbol of (6² · 8)(4² · 6³ · 8)(4² · 6⁵ · 8³). The photochemical property shows that the luminescent emission can be significantly quenched by aromatic azo compounds. The quenching effect coefficient (K_sv) for bis(4-imidazol-1-yl-phenyl)diazene is determined to be 4.1 × 10⁴ m ^–1, indicating the title compound as a potential fluorescent sensing materials.     

Ultrasound-aided synthesis of gold-loaded boron-doped graphene quantum dots interface towards simultaneous electrochemical determination of guanine and adenine biomolecules

To acquire substantial electrochemical signals of guanine-GUA and adenine-ADE present in deoxyribonucleic acid-DNA, it is critical to investigate innovative electrode materials and their interfaces. In this study, gold-loaded boron-doped graphene quantum dots (Au@B-GQDs) interface was prepared via ultrasound-aided reduction method for monitoring GUA and ADE electrochemically. Transmission electron microscopy-TEM, Ultraviolet–Visible spectroscopy-UV–Vis, Raman spectroscopy, X-ray photoelectron spectroscopy-XPS, cyclic voltammetry-CV, and differential pulse voltammetry-DPV were used to examine the microstructure of the fabricated interface and demonstrate its electrochemical characteristics. The sensor was constructed by depositing the as-prepared Au@B-GQDs as a thin layer on a glassy carbon-GC electrode by the drop-casting method and carried out the electrochemical studies. The resulting sensor exhibited a good response with a wide linear range (GUA = 0.5–20 μM, ADE = 0.1–20 μM), a low detection limit-LOD (GUA = 1.71 μM, ADE = 1.84 μM), excellent sensitivity (GUA = 0.0820 µAµM⁻¹, ADE = 0.1561 µAµM⁻¹) and selectivity with common interferents results from biological matrixes. Furthermore, it seems to have prominent selectivity, reproducibility, repeatability, and long-lasting stability. The results demonstrate that the fabricated Au@B-GQDs/GC electrode is a simple and effective sensing platform for detecting GUA and ADE in neutral media at low potential as it exhibited prominent synergistic impact and outstanding electrocatalytic activity corresponding to individual AuNPs and B-GQDs modified electrodes.     

Synthesis and evaluation of simplified functionalized bongkrekic acid analogs

Bongkrekic acid (BKA) is a strong inhibitor of adenine nucleotide translocase (ANT), inducing inhibition of adenosine triphosphate synthesis. We designed and synthesized simplified benzene-ring-containing BKA analogs. The key reaction is the one-pot double Sonogashira reaction, which forms the main skeleton. The analogs were efficiently synthesized in 8–10 longest linear sequence steps. This synthetic method can be applied for the preparation of other analogs having different combinations of carbon chain lengths. Furthermore, the allyloxy group on the benzene ring can be easily replaced by other functional groups. Our preliminary biological evaluation based on mitochondrial inhibitory effects revealed the high potency of the analogs bearing the same carbon chain length as that of BKA. In particular, the prefunctionalized analogs are potential ANT inhibitors.     

Simultaneous Electrodeposition of Reduced Graphene Quantum Dots/Copper Oxide Nanocomposite on the Surface of Carbon Ceramic Electrode for the Electroanalysis of Adenine and Guanine

In this study, simultaneous deposition of copper oxide and electro-reduced graphene quantum dots (ErGQDs) on the surface of carbon ceramic electrode (CCE) was reported. The prepared ErGQDs-CuO/CCE was carefully characterized with Fourier transform infrared spectroscopy, X-ray diffraction, fluorescence spectroscopy, scanning electron microscopy and electrochemical techniques in details. According to scan rate studies in hexacyanoferrate, a remarkable increase in the surface coverage in the presence of ErGQDs was achieved. According to square wave voltammetry results, limit of detection, linear range and sensitivity of the developed biosensor for the simultaneous measurement of Adenine (A) and Guanine (G) were obtained to be 0.041 and 0.111 μM, 0.1–13 μM and 0.25–23 μM, and 4.261 and 1.311 μA μM cm⁻² respectively.     

取代基对腺嘌呤与胸腺嘧啶氢键复合物体系结合能的影响简

优化得到了17个取代胸腺嘧啶与腺嘌呤形成的氢键复合物的结构,并计算了这些复合物的结合能,探讨了胸腺嘧啶上不同取代基对结合能的影响. 结果表明,CF3取代的胸腺嘧啶与腺嘌呤间的结合能大于胸腺嘧啶与腺嘌呤间的结合能,这可能是屈氟尿苷具有阻止病毒及肿瘤扩散功能的原因所在. SO3H,CN和NO2取代的胸腺嘧啶与腺嘌呤间具有更大的结合能,表明这3个基团取代的胸腺嘧啶也可能具有潜在的抗肿瘤作用. 分子中原子理论与自然键轨道分析表明,在所有体系中,氢键N—H…N最强,N—H…O=C次之,C—H…O=C最弱,轨道作用在氢键作用中占有重要地位.     

经ORC处理银衬底上核酸碱基的SERS研究

利用天线共振子模型对银的表面增强喇曼散射(SERS)特性进行了计算和分析.结果显示，银增强因子在近红外的1.38 eV处为最大，达140以上；近紫外3.35 eV、3.90 eV、4.30 eV位置处依次减小，分别为60、48、45；而在可见光区，银增强因子的最大值为70. 在经氧化还原过程(ORC)处理的银片上做了核酸碱基腺嘌呤、尿嘧啶的SERS谱，腺嘌呤的SERS谱虽然存在荧光的影响，但SERS效应明显.尿嘧啶的SERS谱出现4个明锐的峰值，1035 cm－1是所出现的最强的模式，该模式应是尿嘧啶在核酸中存在的SERS环呼吸模式，可作为检测尿嘧啶存在的判定依据.