化学发光酶免疫法检测猪肉中氯丙嗪残留

采用棋盘滴定法确定包被抗原浓度和抗体稀释倍数,通过单因素实验优化了竞争反应时间、磷酸盐缓冲液浓度、甲醇含量、pH值等参数,建立了氯丙嗪的间接竞争化学发光酶免疫检测方法,并考察了方法的特异性、灵敏度和稳定性.结果表明,最佳反应条件为包被抗原浓度为0.05 μg/L;氯丙嗪抗体稀释32000倍;体系缓冲液为含10％甲醇、0.1 mol/L磷酸盐缓冲液(pH 7.0).本方法的IC50为0.12 μg/L;检出限为0.02 μg/L;线性范围0.02～24.78 μg/L;批内和批间相对标准偏差均小于10％.与其它结构类似物没有明显交叉反应.猪肉检测的平均回收率为87.4％～105.6％,与高效液相色谱方法的相关性良好.本方法具有较高的灵敏度和较好的稳定性.     

2,5-二(4’-羧基苯基)-1-苯基吡咯对胺的“点亮”荧光检测

基于水溶性2,5-二(4’-羧基苯基)-1-苯基吡咯的羧酸钠盐(TPP-2COONa)具有质子化荧光淬灭、去质子化荧光增强的特征.在研究了TPP-2COONa的紫外吸收光谱和荧光发射光谱对pH的响应规律的同时,以此为荧光探针,证实了TPP-2COOH对于多种胺类(氨水、二异丙胺、异丙胺和三乙胺)荧光增强响应明显,而对芳香胺(吡咯、苯胺、吡啶)没有任何荧光响应,其中对于氨水最为敏感,在很窄的pH区间和低浓度范围内荧光强度大幅度增长,体现了该探针对于氨水具有良好的选择性和灵敏度,并可简易实现"在线裸眼检测".     

A microenvironment-sensitive fluorescent pyrimidine ribonucleoside analogue: synthesis, enzymatic incorporation, and fluorescence detection of a DNA abasic site

Base-modified fluorescent ribonucleoside-analogue probes are valuable tools in monitoring RNA structure and function because they closely resemble the structure of natural nucleobases. Especially, 2-aminopurine, a highly environment-sensitive adenosine analogue, is the most extensively utilized fluorescent nucleoside analogue. However, only a few isosteric pyrimidine ribonucleoside analogues that are suitable for probing the structure and recognition properties of RNA molecules are available. Herein, we describe the synthesis and photophysical characterization of a small series of base-modified pyrimidine ribonucleoside analogues derived from tagging indole, N-methylindole, and benzofuran onto the 5-position of uracil. One of the analogues, based on a 5-(benzofuran-2-yl)pyrimidine core, shows emission in the visible region with a reasonable quantum yield and, importantly, displays excellent solvatochromism. The corresponding triphosphate substrate is effectively incorporated into oligoribonucleotides by T7 RNA polymerase to produce fluorescent oligoribonucleotide constructs. Steady-state and time-resolved spectroscopic studies with fluorescent oligoribonucleotide constructs demonstrate that the fluorescent ribonucleoside photophysically responds to subtle changes in its environment brought about by the interaction of the chromophore with neighboring bases. In particular, the emissive ribonucleoside, if incorporated into an oligoribonucleotide, positively reports the presence of a DNA abasic site with an appreciable enhancement in fluorescence intensity. The straightforward synthesis, amicability to enzymatic incorporation, and sensitivity to changes in the microenvironment highlight the potential of the benzofuran-conjugated pyrimidine ribonucleoside as an efficient fluorescent probe to investigate nucleic acid structure, dynamics, and recognition events.     

s区金属离子对锰(Ⅱ)配位聚合物的结构构建及性质影响

本文通过在s区金属离子(Li+,Na+,K+,Mg2+,Ca2+)存在下,2,6-吡啶二羧酸(H2pda)或2-吡啶羧酸(picH)与Mn(Ac)2.4H2O的水热合成反应,系统探讨了s区金属离子的电荷和半径对Mn(Ⅱ)配位聚合物的结构构建以及热稳定性和溶解性能的影响。合成了2个混合金属配位聚合物[Na2Mn(pda)2]n(1)和[K2Mn(pda)2]n(2),并通过红外和X-单晶衍射进行了结构表征:1属于正交系,空间群Pnna;2属于单斜系,空间群P2/n。同时应用荧光光谱测试研究了配合物1水溶液的荧光性质。     

Syntheses,Structures and Properties of Lanthanide Coordination Polymers Constructed from Mixed Acid

Two new coordination polymers,[Ln(oba)(ox)0.5(H2O)2]n(Ln = Ho(1),Eu(2);H2oba = 4,4?-oxybis(benzoic acid),H2ox = oxalic acid) have been synthesized under hydrothermal conditions.According to single-crystal X-ray diffraction analyses,complex 1 crystallizes in the monoclinic system,space group P21/c with a = 13.783(2),b =10.0120(15),c = 12.1974(18) ,β = 105.217(2)°,V = 1624.2(4) 3,C15H12O9Ho,Mr = 501.18,Z = 4,Dc = 2.050 g/cm3,F(000) = 964,μ = 4.919 mm-1,λ(MoKα) = 0.71073 ?,GOOF = 1.124,the final R = 0.0239 and wR = 0.0570 for 3310 independent reflections with Rint = 0.0298.Complexes 2 and 1 are isostructural.Oba and ox ligands bridge the Ln(III) ions into 2D layers with(4,4) topology,which are further interlinked into a 3D supramolecular network by hydrogen bonds.TG curves of the two complexes are studied to examine their thermal stabilities.Additionally,complex 2 shows red fluorescence in the solid state at room temperature.     

超高效合相色谱法快速检测纺织品中的8种荧光增白剂

建立了同时检测纺织品中1,2-双(5-甲基-2-苯并恶唑基)-乙烯(PF)、7-二乙氨基-4-甲基香豆素(SWN)、2,2'-(2,5-二苯基硫代)双[5-(1,1-二甲基乙基)]苯并恶唑(OB)、2-[4-[2-[4-(2-苯并恶唑基)苯基]乙烯基]苯基]-5-甲基苯并恶唑(KSN)、1,4-双(2-氰基苯乙烯基)苯(ER-Ⅰ)、1-邻氰苯乙烯基-4-对氰苯乙烯基苯(ER-Ⅱ)、2,2-(1,4-亚萘基)双(苯并恶唑)(KCB)和4,4'-双[2-(2-甲氧基苯基)亚乙基]-1,1'-联苯(FP)8种荧光增白剂的超高效合相色谱(UPC²)检测方法。样品经二甲苯提取、浓缩、定容后,由UPC²进行定性定量分析。以超临界CO₂-甲醇为流动相,梯度洗脱,采用ACQUITY UPC² HSS C18 SB色谱柱(100 mm×3.0 mm,1.8 μm)进行分离。8种荧光增白剂在1.0~20.0 mg/L范围内线性良好(r≥0.9991),定量限(LOQ,S/N=10)在0.70~0.95 mg/L之间。不同添加水平的回收率范围为90.9%~96.5%,相对标准偏差(RSD)为2.8%~4.2%。该方法简单、准确度高、分析时间短,可用于快速检测纺织品中的8种荧光增白剂。     

G-四链体DNA稳定剂的研究进展

人体端粒由富含鸟嘌呤(G)的DNA重复序列组成,该序列在一定的条件下可以形成G-四链体DNA的结构.小分子化合物诱导该结构的形成并使之稳定,不但可以抑制端粒酶的活性或降低癌基因的转录表达而达到抗肿瘤的目的,还可以作为G-四链体DNA的探针,辅助G-四链体DNA生物功能的研究及与之相关疾病的诊断.因此,G-四链体DNA稳定剂的设计是近年来化学生物学的重要前沿领域之一.到目前为止,G-四链体DNA稳定剂主要可分为有机小分子化合物和金属配合物.本文重点综述这两方面特别是后者的最新研究进展.     

Test‐Strip‐Based Fluorometric Detection of Fluoride in Aqueous Media with a BODIPY‐Linked Hydrogen‐Bonding Receptor

The measurement of biologically relevant anions, such as fluoride, is an important task in analytical chemistry, in particular, for dental health and osteoporosis. Although a large number of fluoride probes are known, the applicability under relevant conditions is limited to a few examples. To improve this situation, BODIPY‐amidothiourea dyes with varying hydrogen‐bond donating strengths were developed, the most H‐acidic of which ( 1 c ) could detect F^? from an inorganic source (NaF) in 50 % aqueous solution (DMSO/water 1:1, v/v) with 0.01 ppm sensitivity through selective fluorescence quenching by a photoinduced electron‐transfer (PET) process. Use of the probe and a reference dye with a test‐strip assay and a portable and rapidly recording lateral‐flow fluorescence reader made determination of F^? in neat aqueous solutions, such as spiked water samples and toothpaste extracts, possible in a self‐referenced manner, achieving a detection limit of 0.2 ppm.     

A Multivalent Ligand for the Mannose‐6‐Phosphate Receptor for Endolysosomal Targeting of an Activity‐Based Probe

The ubiquitously expressed mannose‐6‐phosphate receptors (MPRs) are a promising class of receptors for targeted compound delivery into the endolysosomal compartments of a variety of cell types. The development of a synthetic, multivalent, mannose‐6‐phosphate (M6P) glycopeptide‐based MPR ligand is described. The conjugation of this ligand to fluorescent DCG‐04, an activity‐based probe for cysteine cathepsins, enabled fluorescent readout of its receptor‐targeting properties. The resulting M6P‐cluster–BODIPY–DCG‐04 probe was shown to efficiently label cathepsins in cell lysates as well as in live cells. Furthermore, the introduction of the 6‐O‐phosphates leads to a completely altered uptake profile in COS and dendritic cells compared to a mannose‐containing ligand. Competition with mannose‐6‐phosphate abolished all uptake of the probe in COS cells, and we conclude that the mannose‐6‐phosphate cluster targets the MPR and ensures the targeted delivery of cargo bound to the cluster into the endolysosomal pathway.     

Highly oxidized graphene with enhanced fluorescence and its direct fluorescence visualization

We prepared hyper-oxidized graphene (HOG) as a form of graphene derivative by additional oxidation of graphene oxide (GO) sheets. HOG, which formed more functional groups and isolated conjugated clusters on the sheets, accordingly showed high solubility in water and alcohols, high transmittance and film transparence, longer fluorescence decay constant time, and enhanced fluorescence in states of solution and solid. By contrast, GO has much weaker fluorescence in solution and its fluorescence is totally quenched in solid. The influences of concentration, metallic ions, and pH on HOG fluorescence in aqueous solution were also investigated in detail. Due to HOG’s strong fluorescence, direct visualization was realized on substrates and in solution. In addition, direct 3D fluorescence visualizations of HOG phase in polymer composites were achieved. These results show the great potential of HOG in a broad range of applications, from biological labeling, probes, and drug carriers to high-performance composites and nanomanipulation.