Modifying the response of a polymer-based quartz crystal microbalance hydrocarbon sensor with functionalized carbon nanotubes

Pejcic, Bobby; Myers, Matthew; Ranwala, Nilukshi; Boyd, Leigh; Baker, Murray V.; Ross, Andrew

doi:10.1016/j.talanta.2011.06.062

Cited by 35 publications

(23 citation statements)

References 45 publications

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“…At increased plasticizer levels (i.e., 25% w/w), the sensitivities of both plasticizer−PMMA composites were found to be in agreement with log P trends, suggesting that hydrophobic interactions may be the predominate sensing mechanism. Compared to the rubbery polymers studied elsewhere under similar experimental conditions, 25 the hydrocarbon sensitivity and log P correlations for the plasticizer−PMMA composites were somewhat lower (r 2 = 0.7941 for DOP−PMMA and r 2 = 0.7646 for DOS−PMMA), implying that the PMMA response mechanism is also dependent on other factors which will be discussed later. No significant differences were observed in the response times for the different plasticizers.…”

Section: ■ Results and Discussionmentioning

confidence: 61%

Using Plasticizers to Control the Hydrocarbon Selectivity of a Poly(Methyl Methacrylate)-Coated Quartz Crystal Microbalance Sensor

et al. 2012

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Chemical sensors based on a polymer coated quartz crystal microbalance (QCM) generally present poor molecular selectivity for compounds that contain similar functional groups and possess the same chemical properties. This paper shows for the first time that the selectivity and sensitivity of a poly(methyl methacrylate) (PMMA) based QCM sensor can be significantly enhanced for aromatic hydrocarbons by incorporating a plasticizer into the polymer film. The sensor was fabricated by spin coating PMMA onto a quartz crystal, and the influence of plasticizer type and amount on the response was evaluated. It was shown that the hydrocarbon sensitivity of plasticizer-free PMMA is negligible, while the sensitivity of plasticized PMMA was similar to or in some cases greater relative to highly responsive rubbery polymers such as polyisobutylene (PIB). Detection limits of 4.0, 1.5, 0.4, 0.6, and 0.1 ppm were obtained on a PMMA film containing 25% w/w di(2-ethylhexyl) phthalate for benzene, toluene, ethylbenzene, p-xylene, and naphthalene, respectively. We found that at low plasticizer levels (∼10% w/w) the PMMA film was more sensitive toward ethylbenzene and p-xylene over naphthalene when compared to a PIB film under similar measurement conditions. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) measurements were performed to understand the sensing mechanism, and these studies confirmed a higher hydrocarbon uptake by PMMA in the presence of plasticizer. Positron annihilation lifetime spectroscopy (PALS) studies detected variations in the free volume properties of the polymer films as a function of plasticizer content. The accessible free volume as measured by PALS was significantly less in the PMMA films compared to the PIB, and this result correlates favorably with differences in the QCM response pattern. The QCM results have been rationalized in terms of free volume theory which is responsible for the higher hydrocarbon diffusion/sorption with increased plasticizer content.

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Section: ■ Results and Discussionmentioning

confidence: 61%

Using Plasticizers to Control the Hydrocarbon Selectivity of a Poly(Methyl Methacrylate)-Coated Quartz Crystal Microbalance Sensor

et al. 2012

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“…Although organic solvents (i.e., methanol) have been used to disperse and stabilize the VOC during the preparation of stock standard solutions (Kraft and Mizaikoff, 2000;Lima et al, 2011), we avoided their use in this study in order to minimize potential issues that may arise from solvent/matrix effects during the measurement of complex samples. Previous GC-MS studies by us have shown that the loss during the preparation of the BTEX standards directly in deionized water can vary between 20% and 60%, and this depended on the type of hydrocarbon, the concentration and the method of preparation (i.e., vigorous shaking versus ultrasonication, storage time prior to analysis) (Pejcic et al, 2011b). To limit losses by volatility and degradation, all standards were prepared freshly and ATR-FTIR studies were performed within 5 h. All of the standards used in the construction of the calibration curves in the ATR-FTIR studies have been verified using GC-MS.…”

Section: Instrumentation and Sensor Calibrationmentioning

confidence: 99%

“…Over the past several decades there has been significant interest in using chemical sensors to address these and other environmental monitoring issues (Lawrence, 2006;Lieberzeit and Dickert, 2007). Although many sensors are suitable for measuring hydrocarbon concentrations at very low levels (i.e., ppb to ppm or lg/l to mg/ l), the majority of these devices struggle to separate the various signal contributions during the analysis of multi-component hydrocarbon mixtures (Ueyama et al, 2002;Pejcic et al, 2011b). Analyte selectivity remains a major challenge impeding the acceptance of most sensors for assaying complex geochemical and environmental samples.…”

Section: Introductionmentioning

confidence: 99%

Direct quantification of aromatic hydrocarbons in geochemical fluids with a mid-infrared attenuated total reflection sensor

Pejcic

Boyd

Ross

et al. 2013

Organic Geochemistry

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“…QCMs have been proven to be reliable in the field of electrochemistry (Paulo Tde et al, 2013; Sun et al, 2013a, 2013b), in petroleum characterization (Pejcic et al, 2011; Ueyama et al, 2002), in environmental chemistry (Nicolini et al, 2012), material science (Pei et al, 2010) and more interestingly in the development of biosensors (Bouchet-Spinelli et al, 2013; Eom et al, 2013; Guntupalli et al, 2013; Wangchareansak et al, 2013) which are valuable for disease diagnosis. QCMs also found a great interest in the monitoring of the affinity constants defining a given substrate-ligand interaction (Lebed et al, 2006; Li et al, 2013; Mori et al, 2009; Tan et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Concanavalin A–Polysaccharides binding affinity analysis using a quartz crystal microbalance

Coulibaly

Youan

2014

Biosensors and Bioelectronics

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There is no comparative data available on the binding constants of Concanavalin A (Con A) and glycogen and Con A-mannan using Quartz Crystal Microbalance (QCM), cost and time efficient system for biosensor analysis. It is hypothesized that a QCM can be used in its flow injection mode to monitor the binding affinity of polysaccharides to an immobilized lectin, Con A. The biosensor is prepared by immobilizing Con A on a 5 MHz gold crystal by carbodiimide crosslinking chemistry. The attachment efficiency was monitored by Fourier Transform Infrared Spectroscopy. Equilibrium association and dissociation constants describing Con A-polysaccharides interaction are determined in a saturation binding experiment, where increasing concentrations of polysaccharides are run on a Con A-immobilized gold crystal surface, and the frequency shifts recorded on the frequency counter. The molecular weights (MW) of glycogen from Oyster and mannan from Saccharomyces cerevisiae were determined by size exclusion chromatography. The MW for glycogen and mannan are 604±0.002 kDa and 54±0.002 kDa, respectively. The equilibrium association and dissociation constants for ConA-glycogen and Con A-mannan interactions are KA = 3.93 ± 0.7 × 106 M−1 / KD = 0.25 ± 0.06 μM and KA = 3.46 ± 0.22 × 105 M−1 / KD = 2.89 μM ± 0.20 (n = 3), respectively. Their respective frequency and motional resistance shifts relationship (ΔF/ΔR) are 37.29±1.55 and 34.86±0.85 Hz.Ω−1 (n=3), which support the validity of Sauerbrey’s rigidity approximation. This work suggests that Con A-mannan complex could be potentially utilized delivery and the targeting of glucose-rich substances and glycoproteins when fast drug release is desired.

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Modifying the response of a polymer-based quartz crystal microbalance hydrocarbon sensor with functionalized carbon nanotubes

Cited by 35 publications

References 45 publications

Using Plasticizers to Control the Hydrocarbon Selectivity of a Poly(Methyl Methacrylate)-Coated Quartz Crystal Microbalance Sensor

Using Plasticizers to Control the Hydrocarbon Selectivity of a Poly(Methyl Methacrylate)-Coated Quartz Crystal Microbalance Sensor

Direct quantification of aromatic hydrocarbons in geochemical fluids with a mid-infrared attenuated total reflection sensor

Concanavalin A–Polysaccharides binding affinity analysis using a quartz crystal microbalance

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