World Congress on Biosensors 2014

World Congress on Biosensors 2014
Biosensors 2014

Monday 27 February 2012

Just Published: Analytica Chimica Acta

A new issue of this journal has just been published. To see abstracts of the papers it contains (with links through to the full papers) click here:
Selected papers from the latest issue:

Nonenzymatic glucose sensor based on CuO microfibers composed of CuO nanoparticles

25 February 2012, 22:52:23Go to full article
Publication year: 2012
Source: Analytica Chimica Acta, Available online 25 February 2012
Fei Cao, Jian Gong
Fluorine tin oxide (FTO) electrode modified by copper oxide microfibers (CuO-MFs) composed of numerous interconnected CuO nanoparticles (CuO-NPs) for nonenzymatic glucose sensor was prepared by electrospinning precursor containing high percentage content of copper nitrate with subsequent calcination. The results of scanning electron microscope (SEM) showed the size of CuO particles composing CuO-MFs depended on the percentage content of copper nitrate in precursor solution. With increasing the percentage content of copper nitrate, the interconnected CuO-NPs would gradually replace the large-size CuO particles to accumulate the CuO-MFs, which have the potential to provide larger surface area and more reaction sites for electrocatalytic activity toward glucose. As a glucose sensor, the CuO-MFs modified FTO electrode prepared by 40 wt.% of copper nitrate exhibited a high sensitivity of 2321 μA mM cmwith a low detection limit of 2.2 nM (signal/noise ratio (S/N) = 3). Additionally, the application of the CuO-MFs modified FTO electrode as a glucose sensor for biological samples was demonstrated with satisfactory results.

Highlight

► Electrospinning CuO microfibers onto electrodes as glucose sensors were studied. ► The CuO microfibers were composed of CuO particles. ► Size of CuO particles relies on percentage content of copper nitrate in precursor. ► Performance of the sensor depends on size of CuO particles.

Electrochemical sensor for naphthols based on gold nanoparticles/hollow nitrogen-doped carbon microsphere hybrids functionalized with SH-β-cyclodextrin

25 February 2012, 22:52:23Go to full article
Publication year: 2012
Source: Analytica Chimica Acta, Available online 25 February 2012
Gangbing Zhu, Pengbo Gai, Yan Yang, Xiaohua Zhang, Jinhua Chen
Due to awfully harmful to the environment and human health, the qualitative and quantitative determinations of naphthols [1-naphthol (1-NAP) and 2-naphthol (2-NAP)] are of great significance and receive great attention. In this paper, gold nanoparticles (Au NPs)/hollow nitrogen-doped carbon microspheres (HNCMS) hybrids (Au NPs/HNCMS) were prepared and functionalized with thiolated-β-cyclodextrin (HS-β-CD) for the first time, and then applied successfully in sensitive and simultaneous electrochemical detection of naphthols. The results show that the oxidation peak currents of naphthols obtained on the HS-β-CD/AuNPs/HNCMS modified glassy carbon (GC) electrode are much higher than that on the AuNPs/HNCMS/GC, HNCMS/GC and bare GC electrodes. Additionally, compared with other electrochemical sensors developed previously, the proposed electrode results in improved detection limits of about four times for 1-NAP (1.0 nM) and two orders of magnitude for 2-NAP (1.2 nM). The linear response ranges of 1-NAP and 2-NAP are both 2–150 nM.

Highlights

► HS-β-CD/Au NPs/hollow nitrogen-doped carbon microspheres hybrids were synthesized. ► A new electrochemical sensor for naphthols was developed based on the prepared hybrids. ► The sensor shows good analytical performance for simultaneous detection of naphthols.

Glucose Biosensor Based on Three Dimensional Ordered Macroporous Self-doped Polyaniline/Prussian Blue Bicomponent Film

25 February 2012, 22:52:23Go to full article
Publication year: 2012
Source: Analytica Chimica Acta, Available online 24 February 2012
Xiaojun Chen, Zixuan Chen, Rong Tian, Wei Yan, Cheng Yao
In this paper, a three dimensional ordered macroporous self-doped polyaniline/Prussian blue (3DOM SPAN/PB) bicomponent film was fabricated via the inverted crystal template technique using step-by-step electrodeposition. In this bicomponent film, PB not only acted as a redox mediator, but also presented increased stability in neutral or weak alkaline solution by the protection of SPAN layer on the top. A novel glucose biosensor was fabricated based on the large active surface area and excellent conductivity possessed by the 3DOM SPAN/PB film. The applying experimental conditions of the glucose biosensor have been optimized. Under the optimal conditions, the biosensor showed a wide linear range over three orders of magnitude in glucose concentrations (from 2 to 1600 μM) and a low detection limit of 0.4 μM. Moreover, the biosensor exhibited short response time, high selectivity and excellent operation stability, which can be applied to detect the blood sugar in real samples without any pretreatment.

Highlights

► A 3D ordered macroporous self-doped polyaniline/Prussian blue film was prepared. ► In the film, PB revealed good stability in neutral and weak alkalescent solution. ► A novel glucose biosensor was fabricated based on the 3DOM bicomponet film. ► The biosensor showed a linear range of 2-1600 μM and a detection limit of 0.4 μM. ► The biosensor can detect the blood sugar in real samples without any pretreatment.

Detection of influenza A virus based on fluorescence resonance energy transfer from quantum dots to carbon nanotubes

25 February 2012, 22:52:23Go to full article
Publication year: 2012
Source: Analytica Chimica Acta, Available online 24 February 2012
Junping Tian, Huimin Zhao, Meng Liu, Yaqiong Chen, Xie Quan
In this paper, a simple and sensitive approach for H5N1 DNA detection was described based on the fluorescence resonance energy transfer (FRET) from quantum dots (QDs) to carbon nanotubes (CNTs) in a QDs-ssDNA/oxCNTs system, in which the QDs (CdTe) modified with ssDNA were used as donors. In the initial stage, with the strong interaction between ssDNA and oxCNTs, QDs fluorescence was effectively quenched. Upon the recognition of the target, the effective competitive bindings of it to QDs-ssDNA occurred, which decreased the interactions between the QDs-ssDNA and oxCNTs, leading to the recovery of the QDs fluorescence. The recovered fluorescence of QDs was linearly proportional to the concentration of the target in the range of 0.01-20 μM with a detection limit of 9.39 nM. Moreover, even a single-base mismatched target with the same concentration of target DNA can only recover a limited low fluorescence of QDs, illustrating the good anti-interference performance of this QDs-ssDNA/oxCNTs system. This FRET platform in the QDs-ssDNA/oxCNTs system was facilitated to the simple, sensitive and quantitative detection of virus nucleic acids and could have a wide range of applications in molecular diagnosis.

Highlights

► The quantum dots-ssDNA probe was designed for the determination of virus DNA; ► The fluorescence of quantum dots was effectively quenched by carbon nanotubes; ► The addition of target H5N1 DNA restored the quenched fluorescence of quantum dots; ► The proposed method exhibited high sensitivity and good selectivity for H5N1 DNA.

A colorimetric and Surface-enhanced Raman scattering dual-signal sensor for Hgbased on Bismuthiol II-capped gold nanoparticles

25 February 2012, 22:52:23Go to full article
Publication year: 2012
Source: Analytica Chimica Acta, Available online 24 February 2012
Junling Duan, Min Yang, Yongchao Lai, Jingpeng Yuan, Jinhua Zhan
The addition of Bismuthiol II to the gold nanoparticles (AuNPs) solution led to the aggregation of AuNPs with a color change from red to blue. As a result, hot spots were formed and strong surface-enhanced Raman scattering (SERS) signal of Bismuthiol II was observed. However,the Bismuthiol II-induced aggregation of AuNPs could be reversed by Hgin the system, accompanied by a remarkable color change from blue to red. As evidenced by UV-vis and SERS spectroscopy, the variation in absorption band and SERS intensity was strongly dependent on the concentration of Hg, suggesting a colorimetric and SERS dual-signal sensor for Hg. The sensor had a high sensitivity, low detection limits of 2 nM and 30 nM could be achieved by UV-vis spectroscopy and by SERS spectroscopy, respectively. Other environmentally relevant metal ions did not interfere with the detection of Hg. The method was successfully applied to detect Hgin water samples. It was simple, rapid and cost-effective without any modifying or labeling procedure.

Highlights

► A dual-signal sensor for Hgwas developed by mixing Bismuthiol II and AuNPs. ► Colorimetric sensing was achieved based on the Hg-inhibited aggregation of AuNPs. ► Hot spots were formed with the aggregation of AuNPs, allowing SERS detection. ► The method showed high sensitivity and selectivity.

Electrochemical detection of a powerful estrogenic endocrine disruptor: ethinylestradiol in water samples through bioseparation procedure

25 February 2012, 22:52:23Go to full article
Publication year: 2012
Source: Analytica Chimica Acta, Available online 24 February 2012
Noelia A. Martínez, Sirley V. Pereira, Franco A. Bertolino, Rudolf J. Schneider, Germán A. Messina, ...
The synthetic estrogen ethinylestradiol (EE2) is an active component of oral contraceptives (OCs), considered as an endocrine disrupting compound (EDC). It is excreted from humans and released via sewage treatment plant effluents into aquatic environments. EDCs are any environmental pollutant chemical that, once incorporated into an organism, affects the hormonal balance of various species including humans. Its presence in the environment is becoming of great importance in water quality. This paper describes the development of an accurate, sensitive and selective method for capture, preconcentration and determination of EE2 present in water samples using: magnetic particles (MPs) as bioaffinity support for the capture and preconcentration of EE2 and a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs/GCE) as detection system. The capture procedure was based on the principle of immunoaffinity, the EE2 being extracted from the sample using the anti-EE2 antibodies (anti-EE2 Ab) which were previously immobilized on MPs. Subsequently the analyte desorption was done employing a sulfuric acid solution and the determination of the EE2 in the pre-concentrated solution was carried out by square wave voltammetry (SWV).This method can be used to determine EE2 in the range of 0.035–70 ng Lwith a detection limit (LOD) of 0.01 ng Land R.S.D. < 4.20%. The proposed method has been successfully applied to the determination of EE2 in water samples and it has promising analytical applications for the direct determination of EE2 at trace levels.

Highlights

► We developed an electrochemical method for the determination of ethinylestradiol in water samples. ► Modified magnetic particles were employed for the bioseparation and preconcentration procedures. ► The use of magnetic particles offers high selectivity due to antigen-antibody binding specificity. ► The detection was carried out by using a glassy carbon electrode modified with carbon nanotubes.

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