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Talanta
Pergamon Press
Talanta

Pergamon Press

0039-9140

Talanta/Journal TalantaSCIISTPEIAHCI
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    LIFGO: A modular laser-induced fluorescence detection system based on plug-in blocks

    Zhang, Meng-TingPeng, Ya-MeiPan, Jian-ZhangFang, Xiao-Xia...
    7页
    查看更多>>摘要：In this work, a laser-induced fluorescence (LIF) detection system built in a modular assembling mode was developed based on commercial LEGO blocks and 3D printed blocks. We designed and fabricated a variety of 3D printed building blocks fixed with optical components, including laser light source, filters, lens, dichroic mirror, photodiode detector, and control circuits. Utilizing the relatively high positioning precision of the plug-in blocks, a modular construction strategy was adopted using the flexible plug-in combination of the blocks to build a highly sensitive laser-induced fluorescence detection system, LIFGO. The LIFGO system has a simple structure which could be constructed by inexperienced users within 3 h. We optimized the structure and tested the performance of the LIFGO system, and its detection limits for sodium fluorescein solution in 100 mu m i.d. and 250 mu m i.d. capillaries were 7 nM and 0.9 nM, respectively. Based on the LIFGO system, we also built a simple capillary electrophoresis (CE) system and applied it to the analysis of DNA fragments to demonstrate its application possibility in biochemical analysis. The separation of 7 fragments in DL500 DNA markers were completed in 600 s. Because of the features of low cost (less than $100) and easy-to-build construction, we introduced the LIFGO system to the experimental teaching of instrumental analysis for undergraduate students. The modular construction form of the LIF detection system greatly reduces the threshold of instrument construction, which is conducive to the popularization of the LIF detection technique in routine laboratories as well as the reform of experimental teaching mode.
      原文链接:
    • NSTL
    • Elsevier

    Measurement methods of single cell drug response

    Wang, ShuyuSha, XiaopengZhan, ZhikunWang, Ying...
    14页
    查看更多>>摘要：In the last decades, a wide multitude of research activity has been focused on the development of new drugs, and devoted to overcome the challenges of high cost and low efficiency in drug evaluation. The measurement of drug response at the single cell level is a quicker, more direct and more accurate way to reflect drug efficacy, which can shorten the drug development period and reduce research costs. Therefore, the single cell drug response (SCDR) measurement technology has aroused extensive attention from researchers, and has become a hot topic in the fields of drug research and cell biology. Recent years have seen the emergence of various SCDR measurement technologies that feature different working principles and different levels of measurement performance. To better examine, compare and summarize the characteristics and functions of these technologies, we select signalto-noise ratio, throughput, content, invasion, and device complexity as the criteria to evaluate them from the drug efficacy perspective. This review aims to highlight sixteen kinds of SCDR measurement technologies, including patch-clamp technique, live-cell interferometry, capillary electrophoresis, secondary ion mass spectrometry, and more, and report widespread representative examples of SCDR measurement the recent approaches for over the past forty years. Based on their reaction principles, these technologies are classified into four categories: electrical, optical, electrochemical, and mass spectrometry, and a detailed comparison is made between them. After in-depth understanding of these technologies, it is expected to improve or integrate these technologies to propose better SCDR measurement strategies, and explore methods in new drug development and screening, as well as disease diagnosis and treatment.
      原文链接:
    • NSTL
    • Elsevier

    Coupling of spectrometric, chromatographic, and chemometric analysis in the investigation of the photodegradation of sulfamethoxazole

    Marin-Garcia, MarcDe Luca, MicheleRagno, GaetanoTauler, Roma...
    15页
    查看更多>>摘要：A workflow is proposed for the study of the photodegradation process of the sulfamethoxazole (SMX) based on the combination of different experimental techniques, including liquid chromatography, mass spectrometry, UV-Visible spectrophotometry, and the treatment of all the analytical data with advanced chemometric methods. SMX, which is one of the most widely used antibiotics worldwide and has been found at remarkable concentrations in various rivers and effluents over all Europe, was degraded in the laboratory under a controlled source of UV radiation, which simulates the environmental solar radiation (Suntest). Kinetic monitoring of the photo degradation process was performed using UV-Visible spectrophotometric measurements and by further Liquid Chromatography with Diode Array Detector and Mass Spectrometry analysis (LC-DAD-MS). Additionally, the acid-base properties were also investigated to see how the pH can affect the speciation of this substance during the photodegradation process. Based on the Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) application, the proposed chemometric method coped with the large amounts of data generated by the different analytical techniques used to monitor the evolution of the photodegradation process. Their simultaneous analysis involved applying a data fusion strategy and an advanced MCR-ALS constrained analysis, which allowed and improved the description of the complete degradation process, detecting the different species of the reaction, and identifying the possible transformation products formed. A total number of six species were resolved in the degradation process of SMX. In addition to the initial SMX, a second species corresponded to a conformational isomer, and the other four species represented different photoproducts, which have also been identified. Furthermore, three different acid-base species of SMX were obtained, and their pK(a) values were estimated.
      原文链接:
    • NSTL
    • Elsevier

    Synthesis and preliminary exploration of a NIR fluorescent probe for the evaluation of androgen dependence of prostate cancer

    Lu, XinmiaoWu, MuyuWang, SiwenQin, Jingcan...
    6页
    查看更多>>摘要：Purpose: Castration resistance prostate cancer patients showing resistance to the androgen deprivation therapy always have low five-year survival rate and worse prognosis. A responsive NIR fluorescent probe was designed to report the androgen dependence and monitor the development of castration resistance for prostate cancer. Methods: Intratumoral H2S in prostate cancer was closely related to castration resistance. A H2S-responsive NIR probe (HM) was developed as a dependent indicator to report the androgen dependence of prostate cancer. The specificity of HM to H2S and the influence of normal intracellular substrates to the response between H2S and HM were determined. Cell/in vivo animal imaging were performed on PC-3 and LnCAP cell/tumor bearing mice, which presented with androgen independence and androgen dependence, respectively. Results: When HM responded to H2S, strong fluorescence at 770 nm could be rapidly turned on in 5 min with the stokes shift as large as 200 nm. The recognition between HM and H2S showed high specificity. Neither other common substrates showed capacity to turn on HM's fluorescence, nor their existence demonstrated competition. The fluorescence intensity was linearly dependent to the H2S concentration and the limited of detection was 0.15 mu M. When HM was applied to PC-3/LNCaP prostate cancer cell and tumor, the intracellular and intratumoral H2S could be clearly imaged and monitored. Conclusion: HM showing obvious fluorescent behaviors in androgen dependence and independence prostate tumor, which could work as an indicator to reported the androgen dependence of prostate cancer and monitor the development of castration resistance.
      原文链接:
    • NSTL
    • Elsevier

    Magnetic molecularly imprinted polymer for the simultaneous selective extraction of phenoxy acid herbicides from environmental water samples

    Meseguer-Lloret, SusanaTorres-Cartas, SagrarioGomez-Benito, CarmenManuel Herrero-Martinez, Jose...
    8页
    查看更多>>摘要：A selective magnetic molecularly imprinted polymer (MMIP) was synthetized with 4-chloro-2-methylphenoxyacetic acid as template and 4-vinylpiridine as monomer in presence of vinylized magnetite nanoparticles. Scanning electron microscopy, nitrogen adsorption-desorption isotherms, Fourier transform infrared spectrometry and vibrating sample magnetometry were applied to characterize the resulting material. The synthesized MMIP was applied as sorbent in magnetic molecularly imprinted solid-phase extraction (MMISPE) for selective extraction of a mixture of the five herbicides 4-chloro-2-methylphenoxyacetic acid (MCPA), 4-(4-chloro-2methylphenoxy)butyric acid (MCPB), mecoprop (MCPP), fenoxaprop (FEN) and haloxyfop (HAL). Several parameters affecting the extraction conditions were optimized to achieve the best extraction performance. The best MMISPE combined with HPLC-DAD gave detection and quantification limits between 0.33 and 0.71 mu g L-1 and 1.1-2.4 mu g L-1, respectively, were obtained. The precision of the whole method provided RSD values below 7.3%, and the accuracy was demonstrated by the analysis of several water samples of different origins, with recoveries ranged from 77 to 98%. Moreover, a remarkable re-usability of the MMIP sorbent, more than 65 uses without losses in extraction capacity, was obtained.
      原文链接:
    • NSTL
    • Elsevier

    Redox probe-based amperometric sensing for solid-contact ion-selective electrodes

    Sun, XiaotongYin, TanjiZhang, ZipingQin, Wei...
    7页
    查看更多>>摘要：The transformation from the traditional potentiometric response of an ion-selective electrode (ISE) to other signal readout is promising to realize the potential signal amplification. In this work, the redox probes, including ferrocyanide/ferricyanide (Fe(CN)(6)(3-/4-)), hexaammineruthenium (Ru(NH3)(6)(3+)) and ferrocene derivatives, were introduced to read out the potentiometric response for the solid-contact Ca2+-ISE. The mechanism is that the oxidation current of the redox probe on a glassy carbon electrode is modulated by the potential of the ISE through changing the concentrations/activities of Ca2+ under the control of the constant applied potential. Results show that the linear range and the slope sensitivity for detection Ca2+ by using the amperometric signal based on Fe(CN)(6)(4-/3)-redox probe are adjustable through changing the applied potentials. Moreover, the redox probe-based amperometric signal for the solid-contact Ca2+-ISE is found to be related to both of the types of the redox probes and the electrode areas. This work provides a convenient and general method for translating the potential response at mV grade to the amperometric signal at the mu A level, and is promising for detection of ions with high sensitivity by using the ISEs.
      原文链接:
    • NSTL
    • Elsevier

    An aggregation-induced emission fluorescence probe for evaluating the effect of CYP450 changes under tumor chemotherapy

    Lu, PengpengHuang, YanZhang, CaiyunFu, Lili...
    9页
    查看更多>>摘要：Cancer is a complex disease with very high incidence and mortality rates every year. However, cancer drug resistance greatly mitigates the cure rates of tumors, and cytochrome P450 (CYP450) plays an important role in the development of cisplatin resistance. We developed the aggregation-induced emission luminogen (AIEgen) TPE-CYP to monitor the changes in CYP450. The TPE-CYP fluorescent probe was successfully used to assess CYP450 levels in tumor cells and tumor tissue sections. This study presented that CYP450 level in HepG2/DDP cells (cisplatin-resistant cells) was higher than that in HepG2 cells, and the inhibition of CYP450 by 1-ABT effectively improved the tumor resistance. Thus, CYP450 plays a key role in the development of tumor resistance. The synergistic effect of 1-ABT and the chemotherapeutic agent cisplatin was superior to that of cisplatin alone in tumor-bearing mice. The TPE-CYP probe will provide an idea for the clinical implementation of individualized tumor treatment strategies, through the accurate monitoring of CYP450.
      原文链接:
    • NSTL
    • Elsevier

    Construction of a TRFIC strip for rapid and sensitive detection of Ralstonia solanacearum

    Fan, ZiyanHu, LiweiJi, YuanLiu, Shanshan...
    7页
    查看更多>>摘要：The development of a sensitive and rapid screening method for Ralstonia solanacearum is critical for the control of tobacco wilt. In the present study, tissue homogenates of three tobacco varieties (Honda, Yunnan 87 and K326) with different resistance to R. solanacearum, were individually used as additives to the bacteria culture medium. The changes in R. solanacearum secretome were investigated and one of the most abundant secretary proteins with increased expression, polygalacturonase (PG), was selected as a marker for R. solanacearum identification. Then PG gene was cloned into E. coli, and the expressed protein was used as the immunogen to develop monoclonal antibodies. Subsequently, the monoclonal antibody against PG was coupled with synthesized polystyrene microspheres, and a rapid test strip system was developed for the detection of R. solanacearum based on time-resolved fluorescent immunochromatographic (TRFIC) method. Under optimal conditions, the detection limit of the strips could reach 72 cells/mL; while it was 422 cells/mL with a linear range from 4 x 10(2) to 5.12 x 10(4) cells/mL when testing tobacco samples, which is 1000 times lower than that of colloidal gold-labeled strips. Notably, no cross-reactivity was observed with nine tobacco-related pathogens. Finally, this TRFIC strips was applied to detect R. solanacearum existed in the tobacco and soils of fields with or without bacterial wilt. The results demonstrated that this TRFIC strips could distinguish the difference in bacterial concentration existed in tobacco and soil between the two fields. In summary, this test strip is suitable for sensitive, quick screening of R. solanacearum in tobacco.
      原文链接:
    • NSTL
    • Elsevier

    A turn on fluorescent assay for gamma-glutamyltransferase activity and its application in biological imaging

    Gao, JianChen, WenjuanLin, WeixuanYuan, Wei...
    8页
    查看更多>>摘要：gamma-glutamyltransferase (GGT) is widely presented in living cells and overexpressed in many tumor tissues. Therefore, it is generally considered as an important biomarker for the detection of tumor, especially for liver cancer. Accurate determination of its activity is helpful for early diagnosis and treatment of related diseases. In this work, a "turn on" fluorescent probe NSA-GGT for the detection of GGT activity based on glutamine bond was designed and synthesized by employing dansylamino as fluorophore. The probe shows good water solubility and can be well dispersed in aqueous buffer. After incubated with GGT in phosphate buffer, the fluorescence of NSAGGT centered at similar to 523 nm increased over 25-fold. This sensing pattern exhibits an intriguing sensing sensitivity for GGT, and has good performance on intracellular GGT staining, serving as a promising candidate for GGT measurement. Subsequent biological experiments showed that probe NSA-GGT could also be used for fluorescent imaging of GGT activity in living cells and animal tissues.
      原文链接:
    • NSTL
    • Elsevier

    Antibody mounting capability of 1D/2D carbonaceous nanomaterials toward rapid-specific detection of SARS-CoV-2

    Hashemi, Seyyed AlirezaBahrani, SoniaMousavi, Seyyed MojtabaOmidifar, Navid...
    9页
    查看更多>>摘要：Carbonaceous immunosensors are ideal nanoplatforms for developing rapid, precise, and ultra-specific diagnostic kits capable of early detection of viral infectious illnesses such as COVID-19. However, developing a proper carbonic immunosensor requires stepwise protocols to find optimum operating conditions to minimize draw-backs. Herein, for the first time and through a stepwise protocol, activation, and monoclonal IgG antibody mounting capability of multi-walled carbon nanotubes (MWCNTs) at two diverse outer diameters (ODs), viz., 20-30 nm and 50-80 nm, and graphene deny atives (graphene oxide (GO) and reduced graphene oxide (rGO)) were examined and compared with each other toward finding the prime carbonaceous nanomaterial(s) for maximized antibody loading efficiency along with an ideal detection limit (DL) and sensitivity. Next, the effect of common amplifying agents, i.e., Au nanostars (Au NSs) and Ag nanowires (Ag NWs), on the total performance of the best carbonaceous structure was carefully assessed, and the responsible detection mechanism is investigated in detail. Next, the developed carbonaceous immunosensors were assessed via voltammetric and impedance assays, and their performances toward specific detection of SARS-CoV-2 antigen through immunoreaction were examined in detail. The study's outcome showed the superior performance of conjugated rGO-based immunosensor with Au NSs toward specific and quick (1 min) detection of SARS-CoV-2 antigen in biological fluids compared with other 1D/2D carbonaceous nanomaterials.
      原文链接:
    • NSTL
    • Elsevier