一种新型比色荧光双通道水相检测氰根离子的化学传感器

合成了一种新型的,能在含水介质中比色荧光双通道单一选择性识别CN^-的传感器分子1-羟基萘甲叉酰肼乙基-3-羟基萘甲叉酰肼甲基苯并咪唑溴鎓盐(J1)。 在J1的DMSO/H₂O (体积比3:2)HEPES 的缓冲体系(pH=7.2)中分别加入F^-、Cl^-、Br^-、I^-、AcO^-、HSO₄^-、ClO₄^-、H₂PO₄^-、SCN^-和CN^-等阴离子后,只有CN^-的加入会使得溶液颜色发生明显的变化,由无色变为深黄色。 相应地在J1的DMSO/H₂O (体积比4:1)HEPES的缓冲体系(pH=7.2)中加入CN^-,溶液发出明亮的黄色荧光。 这一识别过程,不会受到其它阴离子的干扰。 紫外-可见光谱的最低检测限为1.57×10^-7 mol/L,检测线性范围为3.875×10^-4~2.15×10^-2 mol/L。 荧光光谱的最低检测限为4.63×10^-6 mol/L,检测线性范围为0.8×10^-4~1.60×10^-3 mol/L。 此结果表明,J1是一种良好的用于识别 CN^-的化学传感器,在含水介质中对CN^-具有选择性好、灵敏度高以及抗干扰性强的识别性能。 与此同时,基于J1对于CN^-的高选择性识别我们制备了CN^-的检测试纸,该试纸能够方便、快捷、准确地检测水中的CN^-。     

Conducting Polymer/Ionic Liquid Composite Modified Carbon Paste Electrode for the Determination of Carbaryl in Real Samples

A new method has been described for carbaryl determination using a simple electrochemical sensor. The unique properties of poly‐pPhenylenediamine and ionic liquid were exploited to fabricate carbon paste electrode modified with composite based on conducting polymer/ionic liquid. Electrode surface characterization was performed by electrochemical methods (cyclic voltammetry and electrochemical impedance spectroscopy) and by scanning electron microscopy. Differential pulse voltammetry was employed for the detection of carbaryl in acetate buffer solution. Different parameters affecting the carbaryl response were optimized such as ionic liquid amounts, cycle number of polymerization and monomer concentration, pH, and accumulation time. Under the optimum experimental conditions, a linear response was obtained between 0.5 and 200 μmol/L, with detection limit of 0.09 μmol/L. The developed sensor offered satisfactory results for carbaryl detection in spring water and fruit samples.     

Visual sensing of picric acid in 100% aqueous media based on supramolecular polythiophene assemblies with colorimetric and fluorescent dual response

A colorimetric and fluorometric dual probe based on a water-soluble polythiophene derivative (PMTPBA) was designed and synthesized. It can be applied to determination of picric acid (PA) in 100% aqueous solution. The approach relies on the formation of supramolecular polythiophene assemblies in the presence of PA through electrostatic, charge transfer and π-π stacking interactions. This probe could be utilized for the rapid and visual detection of PA both in aqueous solution and solid support with high specificity and sensitivity. The detection limit of this sensor is as low as 5.0 × 10^-8 mol/L.     

Electrochemical determination of lead using bismuth modified glassy carbon electrode

Electrochemical application of bismuth film modified glassy carbon electrode was studied with the objective of lead detection. Bismuth film on glassy carbon substrate was formed in a plating solution of 2 mmol/L Bi(NO₃)₃, in 1 mol/L HCl at ?1.1 V (vs. Ag/AgCl) for 300 s. Lead was detected by differential pulse anodic voltammetry in acetate buffer of pH 5.0 in the concentration range of 7.5 nmol/L to 12.5 μmol/L. Factors influencing the anodic stripping performance, including deposition time, solution pH, Bi(III) concentration, potential, pulse amplitude, pulse width, have been optimized. Three linear calibration plots in the range 7.5 nmol/L to 0.1 μmol/L, 0.25 to 1 μmol/L, 2.5 to 12.5 μmol/L with regression coefficients of 0.991, 0.986 and 0.978 respectively were obtained. The theoretical detection limit equivalent to three times standard deviation for 7.5 nmol/L lead (n = 5) was calculated to be 5.25 nmol/L utilizing a 5 min deposition time and sensitivity 83.97 A L/mol. The sensitivity and detection limit of the method was compared with reported voltammetric methods for detection of lead and the result obtained was found to be promising for determination of lead.     

一例水溶液中识别铜离子的染料探针

通过罗丹明B与乙二胺反应生成的中间体合成了一例可以对铜离子进行比色检测的探针R-Cu.R-Cu可以实现对在HEPES(5 mmol/L;pH 7.4)溶液中Cu2+的比色可视化识别,加入Cu2+后,R-Cu的吸收明显增强,呈现出罗丹明B的紫红色.探针对Cu2+具有较高的选择性和灵敏性,对其他常见的金属离子具有较强的抗干扰能力.该探针可以在较宽的特别是近中性pH环境下有效检测Cu2+,最低检出限为2.70×10?7 mol/L.     

Colorimetric detection of glucose using a boronic acid derivative receptor attached to unmodifed AuNPs简

A simple, cheap and non-enzymatic colorimetric strategy for glucose detection has been designed based on the interactions between a phenylboronic acid （PBA） derivative, which is coupled with gold nanoparticles （AuNPs） as the colorimetric reporters, and glucose. The PBA-AuNPs hybrid system proposed here exhibits ordered photochemistry behaviors upon the addition of glucose at different pH values. There are two linear regions of glucose concentration for the glucose sensor at different pH values, i.e., between 0.1 mmol/L and 9.8 mmol/L at pH 6 with the detection limit of 64μmol/L and between 0 and 6.5 mmol/L with the detection limit of 48 μmol/L at pH 9, respectively. To test the practicality of the sensor system, we also applied this assay to detect a glucose sample in the artificial saliva.     

汞离子的高灵敏度裸眼识别和荧光传感探针

设计合成了一种以耐尔蓝为母体的Hg2+光学探针分子1-苯甲酰-3-{2-[9-(乙氨基)-10-甲基-9H-苯并[α]苯酚-5-胺基]乙基}硫脲盐酸盐(NBET). 在pH=7.4的Tris-HCl缓冲液中, 探针分子最大吸收波长为640 nm, 此时溶液为淡蓝色; 加入汞离子可以诱导探针分子在640 nm处的吸收降低, 并在556 nm处产生新的吸收峰, 溶液变为浅紫色, 而其它金属离子的加入未引起显著变化, 基于此可对水溶液中的痕量Hg2+进行裸眼识别. 荧光光谱显示, 汞离子可以特异性地猝灭探针分子在660 nm处的荧光发射. 该探针分子的灵敏度、选择性及荧光量子产率高, 激发/发射波长长, 可以实现水溶液中0.005 μmol/L Hg2+的荧光检测.     

磺化杯芳烃修饰的金纳米粒的合成及其对多环芳烃的比色检测

通过偶联修饰的方法合成了水溶性磺化杯芳烃修饰的金纳米粒, 并研了其对多环芳烃的比色检测. 结果表明, 磺化杯芳烃修饰的金纳米粒对蒽具有良好的识别选择性. 该比色探针对蒽的检测限可达到2×10-6 mol/L. 这种比色传感器能够实现现场原位检测.     

多肽在金纳米粒子表面偶联反应效率研究

通过1-(3-二甲氨基丙基)-3-乙基碳二亚胺(EDC)与N-羟基琥珀酰亚胺(NHS)活化反应将多肽偶联到金纳米粒子表面,采用荧光光谱研究其形成的酰胺键的反应偶联效率.考察了实验条件,包括缓冲液的种类(HEPES、Tris-HCl、硼酸、PBS缓冲液)、pH值(pH 6.5~9.0)、缓冲液浓度(10, 25, 40和50 mmol/L)、NHS和EDC的浓度(NHS 0.2~1.0 mol/L,EDC 0.01~0.5 mol/L)及二者比例(0,0.5,1.0,2.0和2.5)、偶联反应时间(4, 8, 12, 24和36 h)等对偶联效率的影响,筛选出最佳实验条件.实验结果表明, 25 mmol/L 4-羟乙基哌嗪乙磺酸(HEPES)缓冲液(pH 7.0), NHS/EDC浓度为0.4 mol/L/0.2 mol/L和24 h的反应时间为EDC-NHS活化反应将多肽偶联到金纳米粒子上的最佳实验条件.本研究结果可为相关研究提供技术参考.     

Sensor Modified with Gold Nanoparticles Stabilized in Dialdehyde Starch/DMSO Matrix for Methyldopa Detection

In this study, gold nanoparticles (AuNP) were synthesized using a novel stabilizer based on dialdehyde starch polymer (DAS) and dimethyl sulfoxide (DMSO) and the nanomaterial was applied to develop a sensor for methyldopa detection. The nanoparticles were characterized by transmission electron microscopy and the proposed sensor was electrochemically characterized by electrochemical impedance spectroscopy, chronocoulometry and square-wave voltammetry. Under optimized conditions (0.1 mol L⁻¹ McIlvaine buffer solution at pH 3.5 and 50 μL AuNP/DAS-DMSO), using square-wave voltammetry, the calibration curve presented a linear range of 0.99 to 19.60 μmol L⁻¹, with a detection limit of 0.50 μmol L⁻¹. The sensor showed good accuracy, with coefficients of variation of 7.8 % (inter-day; n=6) and 5.9 % (intra-day; n=3), and recovery values in the range of 95.3 to 105.2 %. The methyldopa content in a pharmaceutical sample was determined and the results show good correlation with the label value and the method recommended by the Pharmacopoeia, representing a fast and accurate alternative for detecting methyldopa in pharmaceutical products.     

基于谷胱甘肽抑制纳米金催化3,3’,5,5’-四甲基联苯胺与过氧化氢反应比色检测谷胱甘肽

采用具有类似过氧化物酶活性的金纳米粒子(AuNPs)催化四甲基联苯胺(TMB)-H2O2反应,氧化产物(oxTMB)被谷胱甘肽(GSH)还原成TMB,导致吸光度下降,颜色由蓝色变为无色。利用上述现象,设计了一种超灵敏检测谷胱甘肽的比色传感器。在10 pmol/L~10μmol/L范围内,吸光度随GSH浓度呈良好的线性降低关系,检出限为7.5 pmol/L。该方法可以定量检测人血清中的谷胱甘肽。     

Electrochemical sensor for Cd2+ and Pb2+ detection based on nano-porous pseudo carbon paste electrode

An electrochemical sensor based on self-made nano-porous pseudo carbon paste electrode (nano-PPCPE) has been successfully developed, and used to detect Cd²⁺ and Pb²⁺. The experimental results showed that the electrochemical performance of nanoPPCPE is evidently better than both glassy carbon electrode (GCE) and pure carbon paste electrode (CPE). Then the prepared nano-PPCPE was applied to detect Cd²⁺ and Pb²⁺ in standard solution, the results showed that the electrodes can quantitatively detect trace Cd²⁺ and Pb²⁺, which has great significance in electrochemical analysis and detection. The linear ranges between the target ions concentration and the DPASV current were from 0.1–3.0 μmol/L, 0.05–4.0 μmol/L for Cd²⁺ and Pb²⁺, respectively. And the detection limits were 0.0780 μmol/L and 0.0292 μmol/L, respectively. Moreover, the preparation of the nano-PPCPE is cheap, simple and has important practical value.     

2-硫代巴比妥酸修饰金纳米探针高灵敏比色检测三聚氰胺

以2-硫代巴比妥酸(TBA)修饰金纳米粒子为探针,TBA与三聚氰胺通过氢键作用诱导金纳米探针团聚,进而使金纳米胶体颜色由酒红色变为蓝色。 实验优化得最佳反应条件为在乙酸缓冲溶液（pH=7.0）介质中,室温反应15 min。 对不同浓度三聚氰胺进行检测时发现,在0.062~0.18 μmol/L和0.18~6.0 μmol/L之间,A660/A520吸收比率与三聚氰胺浓度呈现良好的线性关系,检出限为0.043 μmol/L。 该方法用于检测牛奶样品中的三聚氰胺的加标回收率为102.8%～105.3%。     

基于层状二硫化钼纳米片比色检测亚锡离子

在醋酸/醋酸钠缓冲溶液(pH=4.5)中, 亚锡离子对层状二硫化钼(MoS₂)纳米片催化过氧化氢(H₂O₂)氧化邻苯二胺(OPD)的显色反应有很强的抑制作用, 据此构建了一种检测亚锡离子的比色传感器. 实验结果表明, 与不加MoS₂纳米片的OPD/H₂O₂比色传感体系相比, MoS₂/OPD/H₂O₂体系检测亚锡离子的灵敏度显著提高, 线性范围变宽. 在优化的条件下, MoS₂/OPD/H₂O₂传感体系检测亚锡离子的线性范围为0.02~3.0 μmol/L, 检出限为8 nmol/L (S/N=3). 该传感体系对检测亚锡离子具有高的选择性, 可用于湖水中亚锡离子的检测.     

Novel colorimetric,photothermal and up-conversion fluorescence triple-signal sensor for rosmarinic acid detection

Rosmarinic acid (RA) is promising as a natural and nontoxic food additive. However, many analysis methods for RA generally depend on large instruments and single signals for quantitative detection. A new up-conversion fluorescence, colorimetric and photothermal multi-modal sensing strategy is developed for the quantification of RA. β-cyclodextrin (CD) modified citric acid (Cit) wrapped NaYF₄:Yb/Er-Cit-CD (Y:Yb/Er-Cit-CD) up-conversion nanocomposite has been synthesized, which emits green fluorescence at 550 nm under 980 nm near-infrared (NIR) excitation. In the presence of oxidized 3,3′,5,5′-tetramethylbenzidine (oxTMB), the green fluorescence is significantly quenched attributed to the fluorescence inner filter effect (IFE) between oxTMB and Y:Yb/Er-Cit-CD. When RA is intervened, blue oxTMB is reduced to colorless 3,3′,5,5′-tetramethylbenzidine (TMB) inducing the recovery of up-conversion fluorescence. At the same time, colorimetric and photothermal signals readout can be easily achieved thanks to the color indication and photothermal effect of the oxTMB. The constructed Y:Yb/Er-Cit-CD/oxTMB sensor displays high sensitivity, visibility and simplicity for RA, and the limits of detection (LOD) for fluorescence, colorimetric and photothermal were 0.004 µmol/L, 0.036 µmol/L and 0.043 µmol/L, respectively. This sensing system is successfully performed for the detection of RA in food samples.     

Development and characterization of an amperometric sensor for triclosan detection based on electropolymerized molecularly imprinted polymer

A novel amperometric sensor based on electropolymerized molecularly imprinted polymer (MIP) for triclosan detection is reported. The sensor was prepared by electropolymerizing o-phenylenediamine (o-PD) on a glassy carbon electrode in the presence of template triclosan. The template can be quickly removed by NaOH solution. After incubating in acetate buffer for 15 min, the sensor response sensitively to triclosan over a linear range of 2.0 × 10^{− 7} to 3.0 × 10^{− 6} mol/L and a detection limit as low as 8.0 × 10^{− 8} mol/L is obtained. This sensor provides an efficient way for eliminating interferences from compounds with similar structures to that of triclosan.     

一种可用于检测苦味酸的水溶性共轭聚合物荧光传感器的制备及应用

制备了一种高灵敏的水溶性荧光共轭聚合物(PPE-OBS), 将其用于苦味酸的荧光检测. 利用质谱、 核磁共振波谱和红外光谱等方法对PPE-OBS进行了表征, 并对其检测苦味酸的条件进行了优化. 结果表明, 在硼酸-氢氧化钠缓冲溶液(pH=9.5)中作用20 min, 苦味酸对PPE-OBS荧光的猝灭效率最大. 在最优条件下, PPE-OBS检测苦味酸的线性范围为1.0~60 μmol/L(R²=0.999), 检出限为0.831 μmol/L(S/N=3). 将PPE-OBS制成荧光试纸用于检测环境样品中的苦味酸, 获得了较好的检测结果.     

玛卡荧光碳点的合成及用于苦味酸的荧光检测

以玛卡为碳源,采用水热法制备荧光碳点。碳点水溶液在激发波长为315 nm时,最大荧光发射波长为425 nm。在玛卡荧光碳点的磷酸盐缓冲液(0.2 mol/L,pH 5.8)中,加入苦味酸,其荧光被猝灭,基于此建立了以玛卡荧光碳点为荧光探针测定苦味酸的方法。本方法检测苦味酸的线性范围为0.4~80 mmol/L,相关系数为0.9978,检出限为110 nmol/L(S/N=3),本方法线性范围宽、灵敏度高、响应快(2 min内),选择性和抗干扰能力良好。用于实际水样中苦味酸的检测,加标回收率为92.0%~110.0%,结果令人满意。     

A New Sensor for Simultaneous Determination of Tyrosine and Dopamine Using Iron(III) Doped Zeolite Modified Carbon Paste Electrode

A new chemically modified electrode is constructed based on iron(III) doped zeolite modified carbon paste electrode (Fe³⁺Y/ZMCPE). The new sensor could be used for the simultaneous determination of the biologically important compounds dopamine (DA) and tyrosine (Tyr). The measurements are carried out using differential pulse voltammetric (DPV) method. The prepared modified electrode shows voltammetric responses of high sensitivity, selectivity and stability for DA and Tyr under optimal conditions, which makes it a suitable sensor for simultaneous trace detection of DA and Tyr in solution. Application of the DPV method demonstrates that in the Briton Robinson buffer solutions (pH=5) containing 50 µmol/L Tyr, there is a linear relationship between the oxidation peaks and the concentrations of DA over the range of 0.1–200 µmol/L, with a detection limit of 0.05 µmol/L (S/N=3). For Tyr a linear correlation between oxidation peak current and concentration of Tyr over the range of 0.5–200 µmol/L (containing 50 µmol/L DA), with a detection limit of 0.08 µmol/L is obtained. The analytical performances of this sensor are evaluated for the detection of DA and Tyr in human serum and a medicine.     

Dual-modal Colorimetric and Fluorometric Method for Glucose Detection Using MnO2 Sheets and Carbon Quantum Dots

A novel dual-modal fluorometric and colorimetric method was developed for glucose detection using MnO2 sheets and carbon quantum dots(CQDs). The glucose could be oxidized by glucose oxidase, in accompanied witli the fbnnation of H2O2 intennediate, which resulted in the decomposition of MnO2 sheets, as well as tlie MnO2 sheets(brown) changed to Mn^2+ ions(colorless), which induced the absorption of MnO2 sheet decreased and the fluorescence of CQDs increased, consequently. The linear detection ranges of glucose are 5-1000 μmol/L by fluorescent method and 5-60 μmol/L by colorimetric method. The limits of detection of these two measurements are 2.11 and 2.18 μmol/L, respectively. This method is easy to conduct, has reasonable sensitive and selectivity, and could be applied for the glucose detection in real human senim.