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Sensors 2010, 10(10), 8953-8962; doi:10.3390/s101008953
Article

Optical Sensing Properties of Dithiocarbamate-Functionalized Microspheres, Using a Polyvinylpyridine-Polyvinylbenzyl Chloride Copolymer

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Received: 12 August 2010; in revised form: 20 September 2010 / Accepted: 25 September 2010 / Published: 8 October 2010
(This article belongs to the Section Physical Sensors)
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Abstract: In this study, a new modified optical chemical sensor based on swellable polymer microspheres is developed using a 5% copolymer of polyvinylpyridine-polyvinyl -benzyl chloride microspheres functionalized as the corresponding dithiocarbamate. This sensor demonstrated significant enhancements in sensitivity, dynamic range and response time. These improvements are related to the presence of pyridine in the polymer backbone, which is believed to increase the space between the groups, thus decreasing steric hindrance, and hence increasing substitution of the dithiocarbamate group. The hydrophilicity of pyridine also allows free movement of the solvent and analyte to and from the inside of the microspheres. These dithiocarbamate-derivatized polymer microspheres were embedded in a hydrogel matrix of polyvinylalcohol cross-linked with glutaraldehyde. This sensor responded selectively to Hg2+ solutions of different concentrations (1 × 10−5 M to 0.1 M). The observed turbidity measured as absorbance varied between 1.05 and 1.75 units at a wavelength of 700 nm. The response is based on the interaction between the metal cations with the negative charges of the deprotonated dithiocarbamate functional group, which led to neutratization of the charges and thus to polymer shrinking. As a result, an increase in the turbidity of the sensing element due to a change in the refractive index between the hydrogel and the polymer microspheres occured. The changes in the turbidity of the sensing element were measured as absorbance using a conventional spectrophotometer.
Keywords: optical sensor; dithiocarbamate-copolymer; polymer swelling optical sensor; dithiocarbamate-copolymer; polymer swelling
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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MDPI and ACS Style

Shakhsher, Z.M.; Odeh, I.M.; Rajabi, I.M.; Khatib, M.K. Optical Sensing Properties of Dithiocarbamate-Functionalized Microspheres, Using a Polyvinylpyridine-Polyvinylbenzyl Chloride Copolymer. Sensors 2010, 10, 8953-8962.

AMA Style

Shakhsher ZM, Odeh IM, Rajabi IM, Khatib MK. Optical Sensing Properties of Dithiocarbamate-Functionalized Microspheres, Using a Polyvinylpyridine-Polyvinylbenzyl Chloride Copolymer. Sensors. 2010; 10(10):8953-8962.

Chicago/Turabian Style

Shakhsher, Ziad M.; Odeh, Imad M.; Rajabi, Inas M.; Khatib, Mahmoud K. 2010. "Optical Sensing Properties of Dithiocarbamate-Functionalized Microspheres, Using a Polyvinylpyridine-Polyvinylbenzyl Chloride Copolymer." Sensors 10, no. 10: 8953-8962.


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