双极制界面电位法测定鲱鱼精dsDNA与联苯胺的结合参

将鲱鱼精dsDNA通过自吸附方式固定在铅笔芯电极(CP)表面制备出DNA/CP.在pH7.38磷酸缓冲溶液(PBS)中,考察联苯胺(BZ)与铅笔芯电极表面鲱鱼精dsDNA相互作用后所导致的DNA/CP零流电位Ezcp变化.结果显示,随着BZ浓度或结合时间的增加,DNA/CP的Ezcp均正移;且当BZ浓度在8.0×10-7～1.0 × 10-5 mol·L-1或结合时间在2～18min内,Ezcp与BZ浓度对数lg[BZ]或结合时间呈正比关系.由此计算出dsDNA与BZ结合反应呈现一级动力学反应方程,其结合比为1∶1,表观结合常数为3.98×106L·mol-1,表观速率常数为2.06×104 s-,半衰期为3.36×10-5s.本方法简单灵敏安全,对拓宽致癌或致毒小分子与DNA作用的研究方法有参考价值.     

Virus meet metal-organic frameworks: A nanoporous solution to a world-sized problem?

Laboratory diagnosis of pathologies caused by virus plays a critical role in outbreak response efforts and establishing safe and expeditious testing strategies. Detection of pathogenic virus using commercial solutions require specific tools and laborious laboratory procedures. This makes the day-to-day on time detection of virus infections the limiting step in any outbreak. The need for new diagnostic tools easily available to poor and rural underdeveloped areas where health infrastructure and trained personnel are scarce is highly desirable. The widely known intrinsic properties of Metal-Organic Frameworks (MOFs) embody them with the potential to overcome some of the challenges inherent to virus detection. MOFs are already components of functional devices capable of perform an uninterrupted detection of molecular targets in real time. In this review, we summarise the few studies concerning the reported MOFs used as sensors for pathogenic virus. We emphasise the structural and physical properties of these materials which can open the possibility for their use in this type of sensors and conclude on how the field can progress to envisage the usage of MOFs by the pharmaceutical industry to develop new sensors for these sub-microscopic infectious agents.     

Size matters: Challenges in imprinting macromolecules

A large number of molecularly imprinted polymers (MIPs) have been investigated and reported over the last decade. Various templates have been successfully exploited and used, leading to significant advances in separation, adsorption, catalysis, sensing, and drug delivery. Among all the templates, small molecules have dominated in the synthesis of MIPs. In contrast, progress made in imprinting macromolecules has been slow, mainly due to the challenges presented by the size, structure and conformational fragility of biological macromolecules. In this review, we focus on discussing some key issues involved in the imprinting of macromolecules from recent publications. The similarity and difference between imprinting small molecules and macromolecules are highlighted. Other aspects relating to polymer design and function are also discussed.     

Electrochemical determination of anticancer drug fulvestrant at dsDNA modified pencil graphite electrode

The interaction of fulvestrant with double-stranded DNA (dsDNA) was studied by means of differential pulse voltammetry (DPV) at dsDNA modified pencil graphite electrode (PGE). The decrease in intensity of the guanine oxidation signals was used as an indicator for the interaction mechanism and sensitive determination of fulvestrant in pH 4.80 acetate buffer (30% ethanol). A linear dependence of the guanine oxidation signals was observed within the range of 1.00–20.00 μg/mL fulvestrant, with a detection limit of 0.41 μg/mL. The determination method was validated according to the standard validation procedure. The proposed method was applied to fulvestrant pharmaceutical dosage form.     

Diallyl sulfides: Selective inhibitors of family X DNA polymerases from garlic (Allium sativum L.)

Diallyl sulfides, organosulfur compounds isolated from garlic (Allium sativum L.), selectively inhibit the activities of mammalian family X DNA polymerases (pols), such as pol β, pol λ and terminal deoxynucleotidyl transferase (TdT), in vitro. The purified fraction (i.e., Sample-A) consisted of diallyl trisulfide, diallyl tetrasulfide and diallyl pentasulfide (molecular ratio: 5.3:3:1). Commercially purchased diallyl sulfides also inhibited the activities of family X pols, and the order of their effect was as follows: Sample-A > diallyl trisulfide > diallyl disulfide > diallyl monosulfide, suggesting that the number of sulfur atoms in the compounds might play an important structural role in enzyme inhibition. The suppression of human cancer cell (promyelocytic leukaemia cell line, HL-60) growth had the same tendency as the inhibition of pol X family among the compounds. Diallyl sulfides were suggested to bind to the pol β-like region of family X pols.     

Graphene-DNA hybrid materials: Assembly, applications, and prospects

Among the carbon-based nanomaterials such as carbon nanotubes, fullerenes, graphene and nanodiamonds, graphene received recently widespread attention owing to its exceptional structural, electronic and mechanical properties and potential applications in various domains. However, all currently known forms of graphene materials are not well dispersible or soluble in most common solvents. This limitation deters to explore the chemistry of graphene at the molecular level and its nanobio device applications. One well known solution to this problem is the use of dispersing agents such as polymers, biopolymers, or surfactants in conjunction with the appropriate experimental conditions. Among the various biomolecules, deoxyribonucleic acid (DNA) has emerged as an appealing biomacromolecule for functional materials due to its biocompatibility and renewability in addition to its very interesting double helix structure, which guarantees a range of unique properties that are difficult to detect in other molecules and polymers. Hence, the combination of graphene (a carbon-based nanomaterial), showing exceptional electronic properties, and DNA (a nanostructured biomolecule), having extraordinary recognition properties, demonstrates a new type of nanobio hybrid material. This, in turn, leads to a successful incorporation of the properties of the two different components in new hybrid materials that present important features for potential applications that range from advanced biomedical systems by means of very sensitive electrochemical sensors and biosensors to highly efficient electronics- and optics-based biochips. This article will focus on the recent advancement of the methods available for the chemical functionalization of graphene using DNA by different interactions (covalent or non-covalent and insertion of DNA through graphene nanopore or nanogap), various types of assemblies, and future prospects. Furthermore, the various potential applications of the resulting new nanobio hybrid materials are also highlighted.