Just Published: Sensors & Actuators B: Chemical

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Sensors & Actuators B: Chemical
http://rss.sciencedirect.com/publication/science/5283

Selected papers from the latest issue:

Recognition of carbon monoxide with SnO2/Ti thick-film sensor and its gas-sensing mechanism

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Wen Zeng , Yanqiong Li , Bin Miao , Liyang Lin , Zhongchang Wang
We have synthesized undoped and Ti-doped SnO2 spheres with a facile yet efficient hydrothermal approach and investigated their microstructures and gas sensing response to carbon monoxide, focusing especially on the impact of Ti doping. We find that gas response of SnO2 is enhanced significantly by doping, the origin of which is clarified in light of a proposed adsorption model. Through a combination of systematic measurements with density-functional-theory calculations, we discuss the enhancement mechanism of the gas-sensing function arising from the doping.

Efficient detection and extraction of cobalt(II) from lithium ion batteries and wastewater by novel composite adsorbent

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Md. Rabiul Awual , Mohamed Ismael , Tsuyoshi Yaita
This study developed a novel composite adsorbent for highly selective and sensitive detection and extraction of cobalt (Co(II)) from lithium-ion batteries (LIBs) and wastewater. The composite adsorbent was prepared by indirect immobilization of 6-((2-(2-hydroxy-1-naphthoyl)hydrazono)methyl)benzoic acid (HMBA) onto mesoporous silica monoliths. The composite adsorbent enhanced the color formation by stable complexation as [Co(II)–HMBA] ⁿ⁺ complexes during detection and sorption operations. The data evident the one-step detection of wide range Co(II) concentrations into interior pore surface coverage of the composite adsorbent from solutions without using high tech instruments, which was unique feature of this adsorbent. The influence of different sorption parameters, such as: initial Co(II) concentration, equilibration time, solution pH and the presence of competing ions and reuses were studied and discussed systematically. The effective pH range for Co(II) ions detection and sorption was neutral pH region and the maximum sorption capacity of the adsorbent was as high as 189.37mg/g. The adsorbed Co(II) was eluted with stripping agent (0.3M HCl) and simultaneously regenerated into initial form for the next capturing operations after rinsing with water. The data also clarified that the composite adsorbent was selectively extracted Co(II) from LIBs even in the presence of high concentration diverse ions. Importantly, the composite adsorbent was retaining functionality in spite of many chemical treatments during sorption–elution-recovery/regeneration cycles. Therefore, the present study revealed that such a low-cost material could be used as potential adsorbent for the selective detection and recovery of Co(II) ions from LIBs and wastewater streams.

Enhancement of the sensitivity of magneto-optical fiber sensor by magnifying the birefringence of magnetic fluid film with Loyt-Sagnac interferometer

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Peng Zu , Chi Chiu Chan , Guo Wei Koh , Wen Siang Lew , Yongxing Jin , Hwi Fen Liew , Wei Chang Wong , Xinyong Dong
Magnetic field sensor by combing magnetic fluid and optical fiber Loyt-Sagnac interferometer is proposed. The sensor takes advantage of the birefringence effect of magnetic fluid. The relative small birefringence of the magnetic fluid is ‘magnified’ by the properly designed optical fiber Loyt-Sagnac interferometric structure. As compared to the reported MF-based sensors, the achieved sensitivity of the proposed sensor is 592.8pm/Oe, which is enhanced by 1–3 orders of magnitude.

Gas sensors based on multiple-walled carbon nanotubes-polyethylene oxide films for toluene vapor detection

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Yong Zhou , Yadong Jiang , Guangzhong Xie , Xiaosong Du , Huiling Tai
Two kinds of toluene vapor sensors with different sensitive film structures, i.e., multi-walled carbon nanotubes (MWCNTs)-polyethylene oxide (PEO) composite film and MWCNTs-PEO bilayer film were fabricated. Both sensors were obtained by airbrushing the sensitive films on interdigitated electrodes (IDE). Response performances of both sensors to toluene vapor at room temperature were investigated. Scanning electron microscope (SEM) was used for morphology analysis of the sensitive films. The experimental results showed that sensors with bilayer films revealed a larger sensitivity than that with the composite films. The response and recovery times of both sensors were within 8s. Moreover, sensors with bilayer films exhibited a modest selectivity to toluene vapor. The sensing mechanisms of both sensors were studied as well.

Silver nanoparticles based selective colorimetric sensor for Cd2+, Hg2+ and Pb2+ ions: Tuning sensitivity and selectivity using co-stabilizing agents

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): V. Vinod Kumar , Savarimuthu Philip Anthony
N-(2-hydroxybenzyl)-valine (VP) and N-(2-hydroxybenzyl)-isoleucine (ILP) organic ligands have been utilized as reducing and surface functionalizing agents in the synthesis of silver nanoparticles (AgNPs) with metal ion interacting functionality. VP and ILP metal interacting ligands functionalized AgNPs exhibited selective colorimetric sensing of toxic Cd²⁺, Hg²⁺ and Pb²⁺ metal ions in aqueous solution at ppm level. The colorimetric sensitivity and metal ion selectivity of VP- and ILP-AgNPs were modulated by incorporating co-stabilizing agents. Importantly, ILP functionalized AgNPs selectively detected Cd²⁺ ions in the polluted ground water samples also.

LSPR optical fibre sensors based on hollow gold nanostructures

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): M.H. Tu , T. Sun , K.T.V. Grattan
Compared to solid gold nanoparticles (AuNPs) which have been widely used for the construction of localized surface plasmon resonance (LSPR) sensors, hollow gold nanoparticles have attracted greater attention recently due to the stronger plasmonic effect that they demonstrate. Combining this with the known advantages of the use of fibre optic technology, a portable, reliable and highly sensitive sensor system has been developed and reported in this study and evaluated for various potential sensing applications. In this work, hollow gold nanocages have been designed and the synthesized specifically for the development of a LSPR-based optical fibre sensor, in this case for Refractive Index (RI) measurement. In doing so, different hollow structures of nanogold have been synthesized and characterized and the experimental results obtained show that the sensitivity of the hollow nanostructure-based LSPR sensor, in response to known RI variations, is closely related to the hollowness of the gold nanocages. It was observed that with the decrease of the wall thickness of the nanocages, the sensitivity of the LSPR sensor created increases dramatically and this is due to the strong plasmonic coupling seen between the interior and exterior fields. Compared to the LSPR sensors based on solid-nanoparticles reported earlier by the authors, the nanocage-based sensor created in this work has demonstrated an excellent sensitivity of 1933nm/RIU, thus showing a significant improvement of at least 3 fold in sensitivity from that prior work.

Hydrothermal preparation and gas sensing properties of Zn-doped SnO2 hierarchical architectures

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Yue Guan , Dawei Wang , Xin Zhou , Peng Sun , Haiyu Wang , Jian Ma , Geyu Lu
A one-step hydrothermal route was used to synthesize undoped and Zn-doped SnO2 hierarchical architectures. The morphologies and structures of the as-prepared samples were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The results clearly revealed that the as-prepared SnO2 hierarchical architectures were composed of many 2 dimensional (2D) nanosheets with the thickness of about 30nm. The gas sensing properties of the as-prepared undoped and Zn-doped SnO2 samples were tested toward various gases. The sensor based on S3 (Zn²⁺/Sn⁴⁺ =0.056) showed excellent selectivity toward ethanol at the operating temperature 213°C, giving a response of about 14.4 to 100ppm, which was about 3.2 times higher than that of sensor based on pure SnO2.

A fluorescent chemosensor for paeonol based on tetramethoxy resorcinarene tetraoxyacetic acid

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Qian Yang , Chaoguo Yan , Xiashi Zhu
A fluorescent chemosensor for paeonol based on tetramethoxy resorcinarene tetraoxyacetic acid (TRTA) in hexadecyltrimethylammonium bromide (CTAB) medium was investigated. The fluorescence of TRTA was quenched by paeonol due to the formation of weak fluorescent inclusion complex (Paeonol–TRTA), and the fluorescence quenching (ΔF = F TRTA − F Paeonol–TRTA) was sensitized in CTAB. Under the optimal conditions, the linear range of calibration curve for the determination of paeonol was 0.02–6.40μg/mL. The detection limit estimated and RSD was 12.05ng/mL, 2.57% (n =3, c =1.0μg/mL). The mechanism of determination was discussed by quenching type analysis, absorption spectrum titrations, Benesi–Hildebrand method, fluorescence quantum yield and IR spectra. This method has also been applied for the determination of paeonol in real sample with satisfactory result.

A novel signal-on DNAzyme-based electrochemiluminescence, sensor for Pb2+

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Yan-fang Wu , Zhi-min Cai , Geng-huang Wu , Ming-cong Rong , Ya-qi Jiang , Chao-yong James Yang , Xi Chen
A novel signal-on electrochemiluminescence (ECL) biosensor for the determination of lead (Pb²⁺) was developed. Background suppression for the ECL detection of Pb²⁺ and hybridization in the presence of Pb²⁺ were realized using a hairpin probe. The 8–17 DNAzymes, which hybridized with their substrate strands, were immobilized onto the surface of a glassy carbon electrode (GCE) via amino coupling method. In the presence of Pb²⁺, the substrate strands were cleaved and released, while DNAzymes alone remained on the GCE surface. The single-stranded DNAzyme could hybridize with a hairpin probe containing an ECL luminophore resulting in quantitative ECL signals. The sequence of the hairpin probe was designed and optimized for hybridizing with single-stranded DNAzyme but not with DNAzyme-substrate double strands. This signal-on strategy possessed low ECL background signals, high sensitivity and selectivity toward Pb²⁺. The ECL sensing approach presented excellent response to Pb²⁺ from 10pM to 100nM with a detection limit of 6.4pM.

On the application of simple matrix methods for electronic tongue data processing: Case study with black tea samples

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Irina Yaroshenko , Dmitry Kirsanov , Liudmila Kartsova , Nabarun Bhattacharyya , Subrata Sarkar , Andrey Legin
The paper is devoted to the application of several simple mathematical methods that can be used for analysis of multisensor system data. RV and modified RV′ matrix correlation coefficients, Tucker's congruency coefficients and canonical correlation analysis can be effectively employed to reveal the similarity degree shared between two different data sets obtained for the same samples. This approach can be particularly useful when the number of available samples is too small to construct and validate quantitative regression models, but still the researcher is interested in getting some numerical estimate of the data quality to judge on electronic tongue applicability for particular analytical tasks. As a case study for this work we analyzed the data from potentiometric and voltammetric electronic tongues acquired during the analysis of black tea samples. These samples were also assessed with standard physicochemical methods and professional sensory panel. The relationships between these four data sets were studied with various matrix correlation techniques.

Development of a continuous-flow polymerase chain reaction device utilizing a polymer disk with a spiral microchannel of gradually varying width

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Kwang Hyo Chung , Yo Han Choi , Seho Park
This paper describes a continuous-flow polymerase chain reaction (CF-PCR) device utilizing a polymer disk, which is equipped with a long spiral microchannel. In the literature, some CF-PCR devices employing a spiral microchannel have been presented to overcome an inherent deployment problem of heaters in CF-PCR of a serpentine microchannel, however, the spiral arrangement also made a problem of non-constant PCR cycle time, which would reduce the PCR efficiency. As a novel solution in this paper, we made the width of the spiral channel decrease gradually in the radial direction in order to keep the cycle time of one round same independent of radial positions and the PCR speed. In the spiral channel of 5.4-m long, through which the PCR reactant is pumped at a constant flow rate, a cycling zone made of thirty spiral rounds corresponding to 30 PCR cycles was placed between a pre-denaturation zone and a post-extension zone, and each zone was designed to have a fixed flow residence time ratio against to the total PCR time. We developed a fast thermal bonding technique minimizing the destruction of the microchannel in the wide polymer disk of 66-mm diameter. A compact heating apparatus was fabricated in order to impose different temperatures at three heating sectors deployed circumferentially in the disk. As a novel trial, the disk is sandwiched by isolated metal plates of constant temperature for stable thermal maintenance. We conducted numerical simulations for the heat transfer to PCR mixture depending on the PCR speed, and discussed on its effect on PCR result. A successful amplification of a human-genome DNA was obtained in less than 10min. The unique architecture used in this CF-PCR device is understood to be well applied to a field-applicable fast PCR.

CuO nanowires based sensitive and selective non-enzymatic glucose detection

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Yuchan Zhang , Yixin Liu , Liang Su , Zhonghua Zhang , Danqun Huo , Changjun Hou , Yu Lei
Copper oxide nanowires (CuO NWs) were prepared by a facile two-step procedure consisting of wet-chemistry synthesis and subsequent direct calcination. The morphology, surface property, and crystal structure of the as-prepared CuO NWs were characterized by SEM, TEM, and XRD. The CuO NWs were further employed to construct a non-enzymatic glucose sensor with excellent performance toward glucose detection in 50mM NaOH solution. The as-developed non-enzymatic glucose sensor showed a fast response time (less than 5s) and a wide dynamic range with excellent sensitivity of 648.2μAcm⁻² mM⁻¹ and 119.9μAcm⁻² mM⁻¹ toward glucose detection at an applied potential of +0.55V and +0.3V (vs. Ag/AgCl), respectively. The Langmuir isothermal theory was employed to fit the obtained calibration curves with high correlation coefficient and the mechanisms for the glucose oxidation promoted by CuO NWs were also discussed. The good selectivity of the CuO NWs based non-enzymatic glucose sensor against electroactive compounds such as ascorbic acid, uric acid, and acetaminophen, and other sugars such as fructose and sucrose at their physiological concentrations were also demonstrated. Furthermore, good accuracy and high precision for the quantification of glucose concentration in human serum samples was attested. These good features indicate that CuO NWs have a great potential in the development of sensitive and selective non-enzymatic glucose sensor.

Sensitive square wave anodic stripping voltammetric determination of Cd2+ and Pb2+ ions at Bi/Nafion/overoxidized 2-mercaptoethanesulfonate-tethered polypyrrole/glassy carbon electrode

24 October 2013, 08:58:24

Publication date: February 2014
Source:Sensors and Actuators B: Chemical, Volume 191
Author(s): Li Chen , Zou Li , Yue Meng , Pei Zhang , Zhaohong Su , Ying Liu , Yi Huang , Yaping Zhou , Qingji Xie , Shouzhuo Yao
Square wave anodic stripping voltammetry was applied to detect Pb²⁺ and Cd²⁺ ions at a glassy carbon electrode modified with overoxidized 2-mercaptoethanesulfonate (MES)-tethered polypyrrole, Nafion and Bi. The PPy–MES interaction was examined by quartz crystal microbalance. Under optimum conditions (5-min preconcentration at −1.2V vs. SCE in pH 4.0 acetate buffer containing 300μgL⁻¹ Bi³⁺), the linear calibration curves ranged from 0.05 to 35μgL⁻¹ for Pb²⁺ and 0.1 to 25μgL⁻¹ for Cd²⁺, respectively, and the limits of detection (S/N =3, S is the signal and N is the noise level) were 0.03μgL⁻¹ for Pb²⁺ and 0.04μgL⁻¹ for Cd²⁺. This method was successfully applied for Pb²⁺ and Cd²⁺ analysis in real water samples.

Graphical abstract