基于钙黄绿素－臧红T荧光共振能量转移检测六偏磷酸钠

在pH8．5的Tris－HCl缓冲溶液中,钙黄绿素作为能量供体（D）可以与藏红T受体（A）发生有效的荧光共振能量转移（FRET）,但加入六偏磷酸钠（SHMP）后,因其与受体发生静电作用破坏了该能量转移体系,使得荧光供体钙黄绿素荧光强度的增加（△FD）与受体藏红T荧光强度的降低（△FA）的比值（△FD／△R）-9SHMP浓度（csHMP）呈良好的线性关系．基于此,建立了一种检测六偏磷酸盐的新方法．在优化条件下,该方法的检测范围为3．0×10^-6-1．0×10^-5mol／L,对6．0×10拍mol／L的六偏磷酸盐连续平行测定11次,其相对标准偏差（RSD）为3．1％．该方法具有选择性好、操作简单和检测速度快等优点,已成功应用于饮料中六偏磷酸钠的分析检测．     

实用型简易激光诱导荧光检测器的研制及性能测试

基于正交型结构,研制了一种简易实用的高效液相色谱激光诱导荧光检测器。以930荧光光度计为骨架,用岛津RF-535荧光检测池,配以自制可调稳压电源,分别以波长532am和405nm的自制激光器为激发光源,以罗丹明B和荧光素为荧光试剂评价体系的性能。罗丹明B的检出限为2．0×10^-8mol／L（S／N〉10）,荧光素的检出限为3．0×10^-10mol／L（S／N〉10）。测试结果表明该检测器达到了设计要求,具有足够的实用灵敏度和较宽的线性范围。     

基于四环素荧光熄灭测定碘的研究

基于碘对荧光试剂四环素的荧光熄灭,建立了测定微量碘的荧光分析方法。在pH10的碱性介质中,最大激发/发射波长分别为400.0nm/509.0nm,四环素的荧光强度与碘浓度的对数呈良好的线性关系,测定碘浓度的线性范围为3.20×10^-7～1.00×10^-4mol/L,检出限为1.30×10^-8mol/L,常见的共存离子不干扰测定。该方法适用于食盐中微量碘含量的测定。     

核酸荧光探针检测铅离子的研究

将8-17 DNAzym e增加2个"G-C"碱基对进行增强热稳定性的结构修饰,并标记上1个荧光基团"FAM"和2个荧光猝灭基团"Dabcyl",设计成双猝灭Pb2+荧光探针。研究了该探针对Cd2+、Zn2+、Mg2+、Cu2+、Mn2+、Pb2+6种二价金属离子的响应,结果表明探针对Pb2+具有很强的特异性,在探针浓度为2.5×10-7mol/L时,Pb2+浓度在8.5×10-8~7.5×10-6mol/L范围内和探针的荧光强度呈线性关系,检出限为8.5×10-8mol/L。该探针可用于Pb2+的定性和定量检测。     

一种响应速率匹配的双反应探针用于荧光识别硫化氢

以6-氟-7-氨基香豆素为荧光基团,氟代叠氮和7-硝基苯并氟咱(NBD)-哌嗪为H_2S反应基团和荧光淬灭基团,合成一种双反应H_2S荧光探针.探针对H_2S的识别性质研究表明,探针的两个反应基团与H_2S响应速率匹配,探针对H_2S具有高选择性和灵敏性,其荧光增强约3600倍,检测极限为4.0×10~(-8)mol/L.酶活性测试表明,探针可用于胱硫醚β合成酶(CBS)酶活性检测和抑制剂筛选.细胞成像实验表明,探针可用于细胞内H_2S的成像研究.     

一种新型三角架罗丹明B荧光探针对Cu～（2＋）识别性能研究

设计、合成了一种新颖的三角架结构罗丹明B衍生物（2）.在乙醇-水（8/1,V/V）介质中,用Tris-HCl控制体系pH为6.8,观察到Cu^2＋对化合物2的荧光及紫外-可见吸收增强性能,同时化合物2对Cu^2＋具有较高的选择性响应.选择最大激发和发射波长为557/577nm,测定了探针2（1.00×10^-5mol·L^-1）对Cu^2＋响应的校准曲线,线性范围为0.10～10.00×10^-5mol·L^-1,相关系数R^2=0.9964（n=15）,检出限为1.129×10^-7mol·L^-1,平行测定5次的相对标准偏差（R.S.D.）为2.2%;以557nm为最大吸收波长测定紫外吸收,Cu^2＋响应的浓度线性范围为0.50～25.00×10^-5mol·L^-1,相关系数R^2=0.9948（n=13）,检出限为3.338×10^-7mol·L^-1.     

巴洛沙星-Tb^3＋-ATP荧光体系的建立及其分析应用

在二元配合物巴洛沙星-Tb^3＋中加入ATP,Tb^3＋在其特征波长545nm处的荧光强度增强,据此建立了新的巴洛沙星Tb^3＋-ATP荧光体系。在最优化实验条件下,增强的荧光强度与ATP的浓度呈良好的线性关系,线性范围为2．0×10^-6-3．0×10^-5mol／L,检出限为8．0×10^-7mol／L。详细的机理研究表明,ATP能与巴洛沙星-Tb^3＋形成大的三元络合物荧光体系。新建立的荧光体系成功地应用于ATP注射液中ATP的定量检测。对不同批次ATP注射液进行加标回收试验,回收率为101％-106％,测定结果的相对标准偏差为1．1％-1．9％（n=5）。     

碘对金纳米棒的融合作用及其在四环素类抗菌素分析测定中的应用

应用等离子共振吸收光谱和扫描电子显微镜,观察了碘和盐酸四环素反应引起的金纳米棒形态的变化．实验表明,单质碘能对金纳米棒产生融合作用,引起金纳米棒径向比的减小和纵向吸收波长的蓝移;但当盐酸四环素存在时,单质碘与盐酸四环素作用,减低了碘的有效浓度,减弱了碘对金纳米棒的融合作用,使金纳米棒的纵向吸收峰随盐酸四环素浓度的增大发生线性红移．据此本文建立了一种测定盐酸四环素的方法．方法的线性范围为5．0×10^-5mol／L～5．0×10^-4mol／L,检测限为2．4×10^-6mol／L（3σ／k）．常见物质不干扰测定．方法成功应用于合成样中四环素测定,回收率在92．8％～107．2％之间,RSD值小于4-3％．用标准加入法测定了3个乳制品厂生产的牛奶中盐酸四环素,表明牛奶中的四环素残余物浓度较低,符合安全标准．     

以Eu（Ⅲ）作荧光探针时间分辨荧光法测定吡哌酸

建立了一种以Eu(Ⅲ)作为荧光探针,时间分辨荧光法测定吡哌酸的新方法。吡哌酸和Eu(Ⅲ)配合后在受到紫外光激发时发生分子内能量转移,配合物发射铕离子的特征荧光。以荧光强度进行条件优化,结果表明,在pH 8.2的缓冲溶液中,加入适量阴离子表面活性剂十二烷基硫酸钠(SDS)后,体系荧光强度大大增强。方法的检出限(3σ)为2×10-8mol/L,测定精度RSD为0.62%(2×10-6mol/L,n=11)。吡哌酸溶液在5×10-8~5×10-6mol/L范围内线性关系良好。该方法可用于吡哌酸片剂及尿液中痕量吡哌酸的测定,药片测定结果与药典方法基本一致。     

一种荧光增强的反应型硫化氢荧光探针

基于二硝基苯醚的硫解反应识别机制,设计合成了羟基芘甲醛为荧光基团的探针分子8-(2,4-二硝基苯酚基)芘甲醛(PCNP),研究了PCNP缓冲溶液分散体系对H_2S的响应.未与H_2S作用时,分子内光致电子转移过程导致探针分子PCNP几乎不发光,当体系中存在H_2S时,PCNP发生硫解反应,光致电子转移过程被阻断,羟基芘甲醛发出橙色荧光.PCNP分子对H_2S响应迅速、灵敏,0.1 mmol·L~(-1)硫化氢存在下10 min内荧光强度响应达到最大值,荧光增强达260倍,反应速率常数为0.20 min~(-1),探针分子对H_2S检测限为0.10μmol·L~(-1),并且具有良好选择性.     

A fluorescent sensing membrane for iodine based on intramolecular excitation energy transfer of anthryl appended porphyrin

A single anthryl appended meso-tetraphenylporphyrin (TPP) dyad has been synthesized and applied in fluorescence sensing of iodine based on the intramolecular excitation energy transfer. The molecular recognition of the sensor is based on the interaction of iodine with inner anthracene moiety of the dyad, while the signal reporter for the recognition process is the TPP fluorescence quenching. Because the emission spectrum of anthracene is largely overlapped with the Soret band absorption of TPP, intramolecular excitation energy transfer interaction occurs between the donor, anthracene and acceptor, TPP. This energy transfer leads to TPP fluorescence emission by excitation of anthracene. The sensor was constructed by immobilizing the dyad in a plasticized poly(vinyl chloride) (PVC) membrane. The sensing membrane shows higher sensitivity compared to the sensors by using anthracene, TPP, or a mixture of anthracene and TPP as sensing materials. Under the optimum conditions, iodine in a sample solution can be determined from 2.04 to 23.6 mmol·L⁻¹ with a detection limit of 33 nmol·L⁻¹. The sensing membrane shows satisfactory response characteristics including good reproducibility, reversibility and stability, as well as the short response time of less than 60 s. Except for Cr₂O₇²⁻ and MnO₄⁻, other common metal ions and anions in foodstuff do not interfere with iodine determination. The proposed method was applied in the determination of iodine in table salt samples. The results agree well with those obtained by other methods. Supported by the National Outstanding Youth Science Foundation of China (Grant No. 20525518), the National Natural Science Foundation of China (Grant No. 20775005), and the National Natural Science Foundation of Hunan province (Grant No. JJ076021)     

Assembly of a tetrathiafulvalene-anthracene dyad on the surfaces of gold nanoparticles: tuning the excited-state properties of the anthracene unit in the dyad

Due to the unique features of the tetrathiafulvalene (TTF) unit, such as the electron-donating ability and presence of methylthio groups, dyad 1 can be assembled on the surfaces of gold nanoparticles, as indicated by absorption, electrochemical, and fluorescent-spectral studies. Dyad 1 can also be disassembled by the addition of thiols. Assembly of dyad 1 on the surfaces of gold nanoparticles leads to the formation of a triad (A1-D-A2), which in turn modulates the photoinduced electron-transfer process within dyad 1. Accordingly, the fluorescence intensity of dyad 1, after assembly with gold nanoparticles, increases, and the fluorescence lifetime is prolonged. Furthermore, the assembly of dyad 1 on gold nanoparticles facilitates photodimerization of the anthracene units of dyad 1. Both fluorescence and photodimerization are associated with the excited-state behavior of the anthracene unit, thus it may be concluded that the excited-state properties of the anthracene unit can be tuned upon complexation with gold nanoparticles.     

Highly Soluble Porphyrin (TPP)-Perylene Diimide (PDI) Dyad and Triad:Synthesis and Spectroscopic Studies

Novel porphyrin‐perylene diimide dyad (TPP‐PDI) and porphyrin‐perylene diimide‐porphyrin triad (TPP‐PDI‐TPP) were synthesized and characterized. Their structure and properties were studied by UV, FL, ¹H NMR, MS, elemental analysis, etc. The variation of fluorescence feature and UV spectra of TPP‐PDI‐TPP triad were investigated at different concentration of CF₃COOH in THF. The incorporation of CF₃COOH leads to the closure of the efficient charge transfer decay. After protonation of porphyrin units, the fluorescence intensity of TPP‐PDI‐TPP triad increased greatly. The fluorescence intensity of TPP‐PDI‐TPP triad restored after addition of triethylamine into the solution. Thus, TPP‐PDI‐TPP triad was a proton‐type fluorescence switch based on acid‐base control. Moreover, different from porphyrin‐perylene type molecular switches reported before, this TPP‐PDI‐TPP triad has wonderful solubility in organic solvents.     

Solid‐State Emission of the Anthracene‐o‐Carborane Dyad from the Twisted‐Intramolecular Charge Transfer in the Crystalline State

The emission process of the o ‐carborane dyad with anthracene originating from the twisted intramolecular charge transfer (TICT) state in the crystalline state is described. The anthracene‐o ‐carborane dyad was synthesized and its optical properties were investigated. Initially, the dyad had aggregation‐ and crystallization‐induced emission enhancement (AIEE and CIEE) properties via the intramolecular charge transfer (ICT) state. Interestingly, the dyad presented the dual‐emissions assigned to both locally excited (LE) and ICT states in solution. From the mechanistic studies and computer calculations, it was indicated that the emission band from the ICT should be attributable to the TICT emission. Surprisingly, even in the crystalline state, the TICT emission was observed. It was proposed from that the compact sphere shape of o ‐carborane would allow for rotation even in the condensed state.     

Highly twisted triarylamines for photoinduced intramolecular charge transfer

9-(N,N-Dianisylamino)anthracene (9DAAA), 9-(N,N-dianisylamino)dinaphth([1,2-a:2'-1'-j]-anthracene (9DAAH), and 9,10-bis(N,N-dianisylamino)anthracene (910BAA) were synthesized as highly twisted triarylamines with potential for photoexcited internal charge transfer. Crystallography of 9DAAA shows its dianisylamino group to be twisted nearly perpendicular to its anthracene unit, similar to a report for 910BAA. The solution fluorescence spectra show strong bathochromic shifts for each of the three molecular systems with strongly decreased quantum efficiency in higher polarity solvents. Solution-phase (ensemble) time-resolved photoluminescence measurements show up to 4-fold decreases in fluorescence lifetime in acetonitrile compared to hexane. The combined results are consistent with photoinduced, transient intramolecular charge-transfer from the bis-anisylamine unit to the polycyclic aromatic unit. Computational modeling is in accord with intramolecular transfer of electron density from the bis-anisylamino unit to the anthracene, based on in comparisons of HOMO and LUMO.     

Uncommon Intramolecular Charge Transfer Effect and Its Potential Application in OLED Emitters

Planarized intramolecular charge transfer(PLICT)state can facilitate the fluorescence process thanks to the relative excellent planarity.Recently,we have discovered that the excited state quinone-conformation induced planarization(ESQIP)occurring on tetraphenylpyrazine(TPP)based derivatives could furnish them with PLICT feature.Unlike to the well-known intramolecular charge transfer,strengthening the electron-donating nature on the donor(D)moiety did not impair the PLICT.The calculation results showed that planarization of the TPP based compounds scarcely accompanied with energy wastage while amount of energy was required for the torsion on geometries.In the polar solvents,the energy consumption for planarization could further decrease,but that for twisting structure would increase.To take advantage of the transformation of the frontier orbitals'distribution,the PLICT type materials would perform a potential application on organic light-emitting diodes(OLEDs).     

A novel donor–donor polymeric dyad of Poly(3‐hexylthiophene‐block‐oligo(anthracene‐9,10‐diyl): Synthesis,solid‐state packing,and electronic properties

A new polymeric dyad of oligo‐anthracene‐block‐poly(3‐hexylthiophene) (Oligo‐ANT‐b‐P3HT) has been synthesized as a donor–donor dyad building block for organic photovoltaics. The polymer dyad and oligomer of anthracene‐9,10‐diyl (Oligo‐ANT) are prepared by Grignard Metathesis. The higher order of crystallinity and molecular chains ordering at solid phase reveal the intrinsic optical and electrical properties of polymeric dyad resulting in relatively higher light harvesting ability compared to the oligo(anthracene‐9,10‐diyl). The UV‐visible spectrum of (Oligo‐ANT‐b‐P3HT) in solution shows broad absorption with two sets of absorption from both anthracene and thiophene core units, covering a wide range of the visible spectrum. The test devices of the blends of polymeric dyad with fullerene C₆₁ (PCBM) show improved photovoltaic performance with a power conversion efficiency of 3.26% upon subjecting to pre‐fabrication thermal treatments. With optimized morphology of the interpenetrating network and the shorter fluorescence lifetime of the annealed dyad/PCBM blends, the effective charge transfer from the donor dyad to PCBM has evidenced. Thus, these studies will allow further synthetic advances to make potential high crystalline polymeric dyads with significantly improved light harvesting capability. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3032–3045     

锌卟啉轴向配合物的光谱特性及配位二聚体分子内的能量传递

通过轴向配位作用构造了ZnTPP-H₂(m-py)TPP卟啉二元体系,研究了配位二聚体的可见吸收光谱和荧光发射光谱特性,考察了二聚体分子内的能量传递过程,观察到能量从激发态ZnTPP^*流向H₂(m-py)TPP。作为对比,研究了ZnTPP-py体系的可见吸收光谱和荧光发射光谱。轴向配位的吡啶引起了ZnTPP荧光光谱明显红移,没有分子内的能量转移过程发生。用吸收光谱和荧光光谱方法计算了加合反应的平衡常数,得到了基本一致的结果。     

Covalently linked bisporphyrins bearing tetraphenylporphyrin and perbromoporphyrin units: Synthesis and their properties

A series of covalently linked bisporphyrins bearingmeso-tetraphenylporphyrin (TPP) and octabromotetraphenylporphyrin (OBTPP) units have been synthesised and characterised. Electrochemical studies on these bisporphyrins showed an anodic shift (∼ 30–60 mV) of the TPP unit and a cathodic shift (∼40-80 mV) of OBTPP in redox potentials. Further, steady-state fluorescence studies on bisporphyrins indicated dramatic decrease in fluorescence quantum yields of the TPP moiety. Electrochemical redox and fluorescence data seem to suggest the possible existence of intramolecular interactions in these bisporphyrins     

Dansyl-anthracene dyads for ratiometric fluorescence recognition of Cu2+

Dansyl-anthracene dyads 1 and 2 in CH(3)CN-H(2)O (7:3) selectively recognize Cu(2+) ions amongst alkali, alkaline earth and other heavy metal ions using both absorbance and fluorescence spectroscopy. In absorbance, the addition of Cu(2+) to the solution of dyads 1 or 2 results in appearance of broad absorption band from 200 nm to 725 nm for dyad 1 and from 200 nm to 520 nm for dyad 2. This is associated with color change from colorless to blue (for 1) and fluorescent green (for 2). This bathochromic shift of the spectrum could be assigned to internal charge transfer from sulfonamide nitrogen to anthracene moiety. In fluorescence, under similar conditions dyads 1 and 2 on addition of Cu(2+) selectively quench fluorescence due to dansyl moiety between 520-570 nm (for 1)/555-650 nm (for 2) with simultaneous fluorescence enhancement at 470 nm and 505 nm for dyads 1 and 2, respectively. Hence these dyads provide opportunity for ratiometric analysis of 1-50 μM Cu(2+). The other metal ions viz. Fe(3+), Co(2+), Ni(2+), Cd(2+), Zn(2+), Hg(2+), Ag(+), Pb(2+), Li(+), Na(+), K(+), Mg(2+), Ca(2+), Ba(2+) do not interfere in the estimation of Cu(2+) except Cr(3+) in case of dyad 1. The coordination of dimethylamino group of dansyl unit with Cu(2+) causes quenching of fluorescence due to dansyl moiety between 520-600 nm and also restricts the photoinduced electron transfer from dimethylamino to anthracene moiety to release fluorescence between 450-510 nm. This simultaneous quenching and release of fluorescence respectively due to dansyl and anthracene moieties emulates into Cu(2+) induced ratiometric change.