基于N-(9-蒽甲基)-L-组氨酸的NOR荧光逻辑门

合成了一个新的组氨酸衍生物, N-(9-蒽甲基)-L-组氨酸(1), 并对其进行了元素分析、电喷雾电离质谱(ESI-MS)、核磁共振氢谱(1H-NMR)和碳谱(13C-NMR)等波谱表征. 考查了pH值及15种不同金属离子对其荧光强度的影响. 实验结果表明, 中性水溶液条件下, Zn2+和Cd2+能使体系荧光增强, 而Pb2+、Co2+、Hg2+、Ni2+和Cu2+等则使体系荧光有不同程度的猝灭.其中, Cu2+和Ni2+猝灭能力最强, 它们与化合物1均形成了物质的量比为1:2的配合物, 络合常数分别为2.88×10⁶和1.12×10⁶ L2·mol-2. Cu2+和Ni2+对化合物1的荧光猝灭为静态猝灭过程. 在此基础上, 以Cu2+和Ni2+作为两个输入信号, 以蒽的特征荧光发射作为输出信号, 构建了一个NOR荧光分子逻辑门.     

基于可识别不同价态铁离子的多控荧光开关及分子逻辑门的构建

本文研究了5-磺基水杨酸(SSA)与多种金属离子的相互作用的荧光光谱,发现Fe3+可以选择性猝灭SSA的荧光,而其他金属离子如Ca2+、K+、Cr3+、Ni 2+Mn2+、Pb2+、Cu2+、Zn2+、Co2+以及Fe2+均不能猝灭SSA的荧光。同时发现,加入EDTA竞争Fe3+或加入盐酸羟胺还原Fe3+均可以使SSA的荧光恢复。可以通过质子(H+/OH-)、配位(Fe3+/EDTA)和化学氧化还原(盐酸羟胺/K2S2O8)三种方式对其荧光进行可逆调控。在此基础上,分别以SSA和SSA-Fe3+体系作为起始状态,构建了两化学输入的NOR、OR和INHIBIT分子逻辑门。     

基于色胺酮衍生物的阴离子探针和分子逻辑门

通过色胺酮与苯肼反应生成一种新型的腙类化合物.在该化合物的DMF溶液中,用含有不同阴离子的四丁基铵盐测试了其对阴离子的识别能力.实验结果表明,加入F-,AcO-和H2PO-4后,溶液由黄色立即变为橙色,而加入Cl-,Br-,I-,ClO-4,NO-3和HSO-4离子则无变化.通过核磁共振波谱证实了探针的识别机制,并设计了一个四输入的分子逻辑门.     

Inhibit化学逻辑门:基于Al3+和Fe3+的β-二酮荧光开关的研究

合成了1,3-二苯基-4-苯乙酰-5-吡唑酮(HDPP-PA)与Al^3 ,Fe^3 形成的配合物,通过元素分析、质谱、红外光谱、紫外-可见吸收、荧光光谱等测试方法,对其组成和结构进行了表征,发现Fe^3 能有效地减弱Al配合物的荧光,为此将HDPP-PA与Al^3 和Fe^3 组成一个具有INHIBIT操作功能的化学逻辑门。     

荧光分子开关的研究进展

荧光分子开关是超分子化学领域的研究热点之一,本文根据开关动作完成的方式对近年来研究的各类荧光分子开关进行了简要的归类总结,并介绍了一些具有特殊功能的荧光分子开关器件.     

分子基逻辑材料*

在适当的条件下分子开关将输入的信息转换为输出信号,利用这一特点,可在分子体系根据二进位布尔逻辑规则实现信号转换。目前,用化学体系进行基本的布尔逻辑功能执行 (PASS、YES、NOT、AND、NAND、OR、NOR、XNOR和INH)都已成为可能。在此基础上,逻辑门的整合与编程,以及更进一步的复杂分子运算开始受到人们的关注。迄今为止,以高灵敏性的荧光输出信号为主,人们在分子水平上设计实现了多种复杂的逻辑电路,包括组合逻辑电路和时序逻辑电路等,并开始涉及信息处理的安全平台设计。本文主要介绍了近年来利用分子荧光开关体系模拟数字逻辑电路过程中所取得的最新进展,对分子逻辑电路研究的热点和问题进行了展望。     

识别中性分子客体荧光传感和开关的研究进展

分子识别是超分子化学的核心概念,而荧光开关PET(photo-induced electron transfer)体系又是分子识别中的重要组成部分,是超分子化学和光物理学科相结合的成就.本文总结了近年来对中性客体分子的荧光传感和开关的研究进展.     

酸碱控制的卟啉-茈酰亚胺分子阵列荧光开关

研究了氯仿溶液中分子阵列N．N-二[对-5’-(间-10’，15’，20’-三苯基卟啉)基-苯基]-3，4：9，10-四羧基茈二酰亚胺(TrPP-PTCDI-TrPP)在不同浓度的三氟乙酸作用下荧光光谱的变化，质子化无金属卟啉的光致激发态成为各种激发态中相对稳定的物种，因此无论激发无金属卟啉基元(λ=439nm)还是]芭酰亚胺基元(λ=491nm)．分子阵列都表现出质子化无金属卟啉生色团的特征荧光发射，酸的引入使激发态下高效率的电荷转移衰变途径被关闭，辐射衰变途径被打开．在溶液中引入三乙胺去质子化使电荷转移衰变途径被打开而辐射衰变途径被关闭，因此分子阵列构成了一个通过酸碱控制的荧光开关．考虑到酸碱中和反应的方便性及分子阵列对不同波段光激发同时敏感的广谱性．该分子阵列开关具有特殊优势．     

亲水性二芳基乙烯荧光分子开关的研究进展

二芳基乙烯荧光分子开关因具有优良的抗疲劳性和双稳态特征而被广泛地研究与应用,亲水化成为其作为荧光开关探针走向应用的关键点之一。本文综述了亲水性二芳基乙烯荧光分子开关当前的研究进展,归纳了实现亲水性的几种重要途径和结构,分析了各种亲水化方法的优缺点,并着重介绍了亲水性二芳基乙烯荧光分子开关作为荧光开关探针在化学传感、生物传感、生物成像以及超分辨成像等领域的应用现状,并指出当前应用研究中存在的一些问题,同时也对其未来的应用前景进行了展望。     

基于PET过程的分子开关型荧光传感器研究进展

基于PET过程的分子开关型荧光传感器研究进展;光诱导电子转移;给体;受体;分子开关;光物理技术     

Fluorescent Molecular Logic Gates and Pourbaix Sensors in Polyacrylamide Hydrogels

Polyacrylamide hydrogels formed by free radical polymerisation were formed by entrapping anthracene and 4-amino-1,8-naphthalimide fluorescent logic gates based on photoinduced electron transfer (PET) and/or internal charge transfer (ICT). The non-covalent immobilisation of the molecules in the hydrogels resulted in semi-solid YES, NOT, and AND logic gates. Two molecular AND gates, examples of Pourbaix sensors, were tested in acidic aqueous methanol with ammonium persulfate, a strong oxidant, and displayed greater fluorescence quantum yields than previously reported. The logic hydrogels were exposed to aqueous solutions with chemical inputs, and the fluorescence output response was viewed under 365 nm UV light. All of the molecular logic gates diffuse out of the hydrogels to some extent when placed in solution, particularly those with secondary basic amines. The study exemplifies an effort of taking molecular logic gates from homogeneous solutions into the realm of solid-solution environments. We demonstrate the use of Pourbaix sensors as pE-pH indicators for monitoring oxidative and acidic conditions, notably for excess ammonium persulfate, a reagent used in the polymerisation of SDS-polyacrylamide gels.     

Logic Information Communication in a Fluorescent Molecular Switch

Based on the chemical‐sensitive fluorescence emission behaviors of the molecular switch 4‐bromo‐5‐methoxy‐2‐(2‐pyridyl)thiazole ( 2‐BMPT ), the communication of logic information between two functional units has been realized. With the rational control of the protonation and coordination reaction of 2‐BMPT , an upstream switching unit (a 1:2 demultiplexer) and two downstream data‐processing units are involved and interconnected in the communication. The two output states of the 1:2 demultiplexer serve as the initial input states of the two parallel downstream data‐processing units, which execute the information communication between the two circuit layers. Furthermore, in the parallel data‐processing layer, the logic gates of INHIBIT and YES accomplish their specific logic functions. Therefore, a molecular cascade circuit composed of an upstream switch and two downstream processing units has been constructed based on the chemical‐modulated fluorescence properties of 2‐BMPT .     

含氧化还原活性基团的荧光分子开关构建与门

报道了一个基于光致电子转移(PET)机理的双稳态荧光分子开关,其中具有氧化还原活性的二茂铁基团作为荧光团蒽PET过程的氧化还原控制单元,通过双Schiff碱C=N键与蒽相连。研究了不同条件下蒽的荧光发射行为。以不同的化学试剂作为体系的输入信号,以不同的荧光发射强度作为输出信号,利用荧光分子开关的质子化反应和氧化反应实现了一个分子水平的逻辑功能。输入信号及其相应的输出结果在分子水平上符合数字逻辑与门的真值表。     

Fluorescent Molecular Logic Gates Driven by Temperature and by Protons in Solution and on Solid

Temperature-driven fluorescent NOT logic is demonstrated by exploiting predissociation in a 1,3,5-trisubstituted Δ²-pyrazoline on its own and when grafted onto silica microparticles. Related Δ²-pyrazolines become proton-driven YES and NOT logic gates on the basis of fluorescent photoinduced electron transfer (PET) switches. Additional PASS 1 and YES+PASS 1 logic gates on silica are also demonstrated within the same family. Beside these small-molecule systems, a polymeric molecular thermometer based on a benzofurazan-derivatized N-isopropylacrylamide copolymer is attached to silica to produce temperature-driven fluorescent YES logic.     

Connectable DNA Logic Gates: OR and XOR Logics

Modern computer processors are based on semiconductor logic gates connected to each other in complex circuits. This study contributes to the development of a new class of connectable logic gates made of DNA in which the transfer of oligonucleotide fragments as input/output signals occurs upon hybridization of DNA sequences. The DNA strands responsible for a logic function form associates containing immobile DNA four‐way junction structures when the signal is high and dissociate into separate strands when the signal is low. A basic set of logic gates (NOT, AND, and OR) was designed. Two NOT gates, two AND gates, and an OR gate were connected in a network that corresponds to an XOR logic function. The design of the logic gates presented here may contribute to the development of the first biocompatible molecular computer.     

Fluorescent Logic Gates Chemically Attached to Silicon Nanowires

I′m in the mood for dansyl : A chemically controlled fluorescent logic gate was formed by grafting a dansyl unit onto silicon nanowires (SiNWs; see picture). The logic gate was operated by utilizing pH changes, Hg^II, and Cl^? or Br^? ions as inputs and the fluorescence of the modified SiNWs as output. The modified SiNWs could perform as a three‐input logic gate that combines the YES and INH operations.

     

Molecular Switches and Multiple Logic Gates Based on 4-(2-Pyridylazo)resorcinol

A simple‐structured 4‐(2‐pyridylazo)resorcinol (PAR) system presents interesting properties with dual fluorescent outputs. Modulated by solution pH two kinds of reversible switch behaviors, "ON‐OFF" and "OFF‐ON", were realized with the PAR system. Stimulated by different combination of external stimulus, such as metal ions, UV irradiation and solution pH, the PAR system could perform multiple logic functions including three inputs AND, two inputs INHIBIT and combinatorial "NOR/AND" in parallel. The operation of the designed system is very simple and detected with a high sensitive fluorescent signal.