MOFs传感器在癌症及其生物标志物检测中的应用

癌症是世界上最致命的疾病之一,因此癌细胞的有效捕获和敏感检测对基础研究以及临床诊断和治疗都具有重要意义.基于金属有机骨架(MOFs)的催化活性和固有的发光性能等特点,MOFs已被成功地开发为传感平台实现对癌症及其标志物的检测.综述了基于MOFs的电化学、荧光、电化学发光、比色传感器在癌细胞及核酸、蛋白质等生物标志物检测...     

Comparison of amperometric and UV-spectrophotometric monitoring in the HPLC analysis of pesticides

Summary Studies have been carried out to compare different detection techniques including amperometric detection in the reductive and oxidative mode and UV detection following the HPLC separation of pesticides. By the example of 4,6-dinitro-o-cresol (DNOC), 2-sec-butyl-4,6-dinitrophenol (Dinoseb) and 2-tert-butyl-4,6-dinitrophenol (Dinoterb), it is shown that the electrochemical detection exhibits higher sensitivities than the UV-technique. The detection limits are in case of the oxidative amperometric technique 0.1 ng for all pesticides, in the reductive mode 0.3 ng for DNOC and 1 ng for Dinoseb and Dinoterb. By UV-monitoring the detection limits were found to be 2 ng for DNOC and 24 ng for Dinoseb and Dinoterb.     

Study of the peak broadening due to detection in the electrophoretic separation of DNA by CE and microchip CE and the application of image sensor for ultra‐small detection cell length

Narrow peaks are important to high‐resolution and high‐speed separation of DNA fragments by capillary electrophoresis and microchip capillary electrophoresis. Detection cell length is one of the broadening factors, which is often ignored in experiments. However, is it always safe to neglect detection cell length under any condition? To answer this question, we investigated the influence of detection cell length by simulation and experiments. A parameter named as detection cell length ratio was proposed to directly compare the detection cell length and the spatial length of sample band. Electrophoretic peaks generated by various detection cell length ratios were analyzed. A simple rule to evaluate the peak broadening due to detection cell length was obtained. The current states of the detection cell length of detection system and their reliabilities in capillary electrophoresis and microchip capillary electrophoresis were analyzed. Microchip capillary electrophoresis detection with an ultra‐small detection cell length of 0.36 μm was easily achieved by using an image sensor.     

Fluorescamine Post-Column Derivatization for the HPLC Determination of Cephalosporins in Plasma and Urine

Abstract

A post-column fluorescamine derivatization procedure is proposed for the determination of cephalosporins having an α-primary amino group in their side chain (cefaclor, cephalexin, cephradine, cefroxadine, cefaloglycine and cefadroxil). The linearity, repeatability and detection limits of fluorescence emission and UV absorption detection are compared under the same chromatographic conditions. Fluorescence detection is about two times more sensitive than UV absorption detection. Application to the determination of these cephalosporins in plasma and urine shows an improved selectivity by comparison with UV detection.     

A study of the relation between the limit of detection and the limit of quantitation in inductively coupled plasma spectrochemistry

The limit of quantitation based on a repeatability threshold concept is compared with the limit of detection in induction coupled plasma atomic emission spectrometry (ICP-AES) and induction coupled plasma mass spectrometry (ICP-MS). A 5%-based limit of quantitation would normally correspond to 10 times the 3-σ based limit of detection. However, because of a possible lack of linearity of the calibration graph at low concentrations, some additional noise not taken into consideration and the possible use of time-correlated multichannel detection, this ratio of 10 cannot be used in every case. It is suggested that a suitable way of determining the limit of quantitation is to establish the plot of the percentage relative standard deviation (RSD) of the net signal as a function of the concentration in a range from the limit of detection to 50 times this limit.     

毛细管电泳和毛细管电色谱技术在农药残留检测中的应用

由于毛细管电泳（CE）和毛细管电色谱（CEC）具有所需样品体积小、分离效率高等特点,越来越多的学者已将它们应用到农药残留（简称农残）检测中,并将它们同各种不同的检测器以及样品浓缩方法相结合,以提高检测的灵敏度。本文对CE和CEC两种方法中所涉及的常见的样品预浓缩方法进行了简要的介绍。对各种不同类型的检测器（如紫外检测、荧光检测、电化学检测以及质谱检测等）的优缺点及其在农残检测中的应用情况进行了评述;同时对手性农药的CE和CEC分离检测情况进行了特别介绍;并对CE和CEC在农残分析与检测中的应用前景进行了展望。     

Detection limits and quantitation limits in the view of international harmonization and the consequences for analytical laboratories

 In the literature and in daily work there exist many different models to describe detection limits and quantitation limits in the chemical measurement process (CMP). It is still an open question whether the evaluation of detection and quantitation limits should be an one-off process carried out during the validation of a CMP, or whether it should be a continuous process. Because of these reasons many laboratories have difficulties to interprete such values. It is necessary that the official standardization bodies should do some efforts in the international harmonization of the special standards concerning detection and quantitation limits. Received: 3 November 1997 · Accepted: 25 January 1998     

Comparison of the Possibilities of Thermal-Lens Detection in Capillaries and Microchips

The conditions of thermal-lens detection are compared for samples with small path lengths: capillaries and microchannels of chemical microchips. The optimum parameters of the optical configuration of a thermal lens spectrometer (beam diameters and their in-sample ratios, and the detector position) were calculated from the theory and confirmed experimentally. The limits of detection of a model chemical substance (ferroin) are estimated at 1 × 10^–8 M for microchips and 5 × 10^–8 M for capillaries. The absolute limits of detection are the same and equal to 3 × 10^–17 M. The advantages and disadvantages of thermal lens detection in capillaries and microchips are discussed.     

生物样品中神经递质的定量测定及其应用研究进展

神经递质（NTs）是神经传递的内源性化学信使，在大脑功能中发挥重要作用。中枢神经系统中神经递质浓度的变化与许多精神和生理疾病有关。神经递质的测定已成为疾病诊断和监测以及治疗干预的重要手段，有效的神经递质体内监测对于疾病诊疗乃至新药研发都至关重要。该文就近年来神经递质的检测方法，包括仪器检测法、电化学检测法以及一些新型检测方法等进行综述，并总结了目前神经递质检测在一些疾病研究中的应用进展。     

免疫亲和柱在兽药残留检测应用中的研究进展

免疫亲和柱(IAC)是一种有效的兽药残留检测净化技术,可以简化样品净化过程并且提高待测物的提取效率,近几年在兽药残留检测中得到广泛应用,并表现出良好的发展前景。本文简要叙述了IAC的原理、制备过程以及在各种抗微生物类兽药检测中的应用,就IAC对目前已研制出的抗微生物药的残留检测及净化效果进行综述,并展望了IAC在未来兽药残留检测应用中的发展趋势,为研究者提供参考和研发思路。     

分析化学中“检出限”的物理意义及测定方法探究

阐述了分析化学中各类分析方法的检出限的物理意义、测定方法及可能存在的问题,并论述了经典的检出限定义的局限性。在利用凝血酶适配体与凝血酶的特异性结合抑制Pt纳米颗粒对量子点荧光猝灭检测凝血酶和基于CuGeO_3纳米线和葡萄糖氧化酶(GOx)修饰的玻碳电极(GCE)生物传感器测定葡萄糖的分析方法中,由于测定信号与被检测物质浓度或浓度的对数成负相关关系,导致分析方法的检出限与经典的检出限测定产生一定的冲突,出现了测定精密度越高,检出限越差的异常情况。     

化学反应—气相色谱法测定蔬菜中杀虫双残留量

本文介绍了一种运用化学反应转化，气相色谱法快速测定蔬菜中杀虫双残留量的方法，其检测限为０．０１ｍｇ／ｋｇ。     

Application of Carbon Nanotubes in the Extraction and Electrochemical Detection of Organophosphate Pesticides: A Review

Recent trends and challenges in developing carbon nanotubes (CNT) based sensors and biosensors for the detection of organophosphate (OP) pesticides and other organic pollutants in water are reviewed. CNT have superior electrical, mechanical, chemical, and structural properties over conventional materials such as graphite. At the same time CNT based sensors and biosensors are more efficient compared to the existing traditional techniques such as high-performance liquid chromatography or gas chromatography, because they can provide rapid, sensitive, simple, and low-cost on-field detection. The measurement protocols can be based on enzymatic and non-enzymatic detection. The enzyme acetylcholinesterase (AChE) is used with CNT for fabricating ultrasensitive biosensors for OP detection involving different immobilization schemes such as adsorption, crosslinking, and layer-by-layer self-assembly. This protocol relies on measuring the degree of enzyme inhibition as means of OP quantification. The other enzyme used along with CNT for OP detection is organophosphate hydrolase (OPH) which hydrolyzes the OP into detectable species that can be measured by amperometric or potentiometric methods. Different forms of CNT electrode materials can be used for fabricating such electrodes such as pure CNT and composite CNT. Due to their large surface area and hydrophobicity, CNT have also been used for the extraction and non-enzymatic electrochemical detection of OP with very high efficiency. The application of CNT and their novel properties for the adsorption and electrochemical detection of OP compounds is discussed in detail.     

Analysis of proguanil and its metabolites by application of the sweeping technique in micellar electrokinetic chromatography

The method of applying large sample volumes in micellar electrokinetic chromatography termed sweeping is applied to determine the conservative limits of detection of some basic drugs in plasma and urine. The biguanides proguanil, 4-chlorophenylbiguanide and cycloguanil are used as models of basic drugs and the limits of detection obtained compared with those previously reported for capillary zone electrophoresis using field-amplified sample injection (FASI) and also by LC using off-line preconcentration. It is found that the sweeping method can be applied to extracts of such biological matrices. The limits of detection obtained by sweeping are improved over FASI for plasma but not for urine and the limits of detection are higher than those reported for LC, for these compounds.     

Determination of free formaldehyde in the presence of donators in cosmetics by HPLC and post-column derivation

Summary The determination of free formaldehyde in the presence of its donators in cosmetic samples by a combination of reversed phase chromatography and post column reaction detection is described. The free formaldehyde is separated on a RP column with water as eluent from interfering formaldehyde-containing compounds and consecutively determined by the lutidine method in a reaction detector with knitted open tubes. With detection in the visible (420nm) the minimum detectable quantity is 40 ppb, with fluorimetric detection 15 ppb. The sample clean-up procedure for cosmetic products ranging from mascara to shampoo is by extracting the formaldehyde with water of pH 3, where the decomposition rate of the donators is minimal. Smaller amounts of free formaldehyde are always found compared to the standard lutidine method.     

Sodium-lead alloy in the decomposition of organic samples for the detection of heteroelements

The decomposition of organic samples using open-tube fusion with sodium-lead alloy was demonstrated to be safe, complete, and controlled, in most cases. The detection of heteroelements in the fusion mixture of common organic samples was successful with samples of 10 to 20 mg. Detection of chlorine and nitrogen by classical methods in “difficult” compounds was secured, and the detection of fluorine in the fusion mixture of fluorocompounds extended the use of the alloy into this area. The use of the pyrazolone color reaction in the detection of nitrogen allowed the detection of more minute amounts of nitrogen than was previously detected using Prussian blue formation. The detection limits for heteroelements in organic samples were in the low microgram region. The application of sodium-lead alloy in quantitative work was briefly studied and will be considered in greater detail in the future.     

Solubilisation and binding characteristics of a recombinant beta2-adrenergic receptor expressed in the membrane of Escherichia coli for the multianalyte detection of beta-agonists and antagonists residues in food-producing animals

The on-line incorporation of cloud point extraction (CPE) to flow injection analysis (FIA) was previously based on the use of a cotton-packed column to entrap the analyte-containing surfactant aggregates after salt-induced CPE, and then the preconcentrated analyte was eluted into a separate detection cell for subsequent chemiluminescence (CL) detection (via the peroxyoxalate CL reaction). In the work, the on-line CPE/FIA technique was improved by the following: (1) sample preconcentration and CL detection were both carried out directly inside the collection column, thus avoiding the decrease in detection sensitivity due to sample dispersion and dilution, and (2) CL detection was performed through the reaction between nitrite and hydrogen peroxide, which is compatible with aqueous samples and should allow for chemical excitation to occur more efficiently inside the collection column. In addition to more effective sample preconcentration, the CL detection of the entrapped analytes directly inside the collection column, i.e., a unique heterogeneous microenvironment in which analyte-containing surfactant aggregates were embedded within the densely packed filtering material, may also contribute to the overall increase in CL intensity (e.g., a CL enhancement factor of ca. 1000). Under optimum experimental conditions, the calibration curve was found to be linear for the CL detection of bilirubin (5 to 120 μg L⁻¹), the limit of detection (S/N = 3) was 1.8 μg L⁻¹, and the R.S.D. was ca. 2.6% (n = 30) for 20 μg L⁻¹ bilirubin. Good agreements were obtained for the determination of total bilirubin in certified reference human serum samples between the present approach and an established clinical method.     

氟硼二吡咯探针在肿瘤检测中的应用

目前,肿瘤是世界上死亡率最高的疾病之一,早期肿瘤细胞的检测对于肿瘤的预防和治疗具有重要意义。当前针对肿瘤细胞的检测手段主要有X光、计算机断层扫描(CT)、磁共振成像(MRI)等,但借助这些手段检测出来的肿瘤细胞通常已生长到中后期,极不利于肿瘤的治疗。荧光成像作为生命科学研究领域常用的手段之一,近年来被用于肿瘤细胞检测,与其他检测方法相比,具有微创、高效、低成本和更加灵敏等优势。氟硼二吡咯(BODIPY)荧光染料作为荧光成像的工具之一,因具有荧光量子产率高、稳定性好、易于修饰等独特优势,被广泛应用于肿瘤细胞检测领域。与常规检测手段相比,BODIPY探针可以靶向肿瘤细胞内细胞器或肿瘤标志物,达到检测早期肿瘤细胞的目的。本文综述了靶向不同标记分子的BODIPY探针的应用,并分析了BODIPY探针的作用机理,以期为肿瘤的临床检测提供更加方便、快捷、直观、灵敏的工具。     

血清HCG、孕酮联合检测在早期先兆流产治疗中的价值分析

目的通过研究探讨血清β-HCG、孕酮联合检测在早期先兆流产治疗中的临床价值。方法随机选取广东省中山市东升镇东升医院2015年1月—2016年9月期间收治的100例早期先兆流产患者作为研究对象,并按随机数字分组法将所有入选患者分为观察组与对照组(各50例),观察组给予血清β-HCG、孕酮联合检测,对照组仅给予血清孕酮检测,分析比较两组患者检验的有效率。结果观察组经联合检测后血清β-HCG、孕酮水平较仅给予血清孕酮检测对照组的水平低(P0.05);观察组经血清β-HCG、孕酮联合检测后临床检验有效率显著优于仅给予血清孕酮检测的对照组,其临床检验的敏感度、阴性预测值及诊断准确率均显著优于仅给予血清孕酮检测的对照组(P0.05)。结论血清β-HCG、孕酮联合检测具有较高的诊断准确率,在早期先兆流产诊断中更具有指导意义,有利于临床根据血清β-HCG、孕酮检测值采取有效治疗措施。     

Evaluation of extraction buffers using the current approach of detecting multiple allergenic and nonallergenic proteins in food

The detection of food allergens has been a challenge because of the increasing need to ensure the absence of undeclared allergens in foods. The current trend in the detection of some food allergens, like peanuts, is based on the detection of multiple allergenic and nonallergenic proteins, and this is the approach that kit manufacturers have adopted. Because commercial kits differ in their ability to detect allergens, regulatory agencies, the food industry, and kit manufacturers are working together to standardize the detection methods. Three kits for the detection of peanuts have been evaluated for performance by the AOAC Research Institute. For this evaluation, a peanut butter suspension was used as a reference material. Several kit components contribute to between-kit analytical variation, even when the same sample is used. One component of commercial kits, which may be contributing to this variability, is the sample extraction buffer. In this study, differences in extractability of 3 allergenic foods were evaluated by using 4 different extraction buffers. The conclusion is that optimum allergen extractability was buffer-dependent, and no single buffer is appropriate for use as a universal extraction solution for all allergenic foods. Therefore, a thorough evaluation of sample preparation buffers needs to be performed for every individual allergenic food. In light of the results obtained, the current approach used for detection of peanut allergens based on the detection of multiple allergenic and nonallergenic proteins is being analyzed.