Silicomolybdate‐Incorporated‐Glutaraldehyde‐Cross‐Linked Poly‐L‐Lysine Film Modified Glassy Carbon Electrode as Amperometric Sensor for Bromate Determination

Abstract

Silicomolybdate-doped-glutaraldehyde-cross-linked poly-l-lysine (PLL-GA-SiMo) film modified glassy carbon electrode was successfully prepared by means of electrostatically trapping the silicomolybdate anion in PLL-GA cationic coating. The PLL-GA-SiMo film was stable and the charge transport through the film was fast. The modified electrode shows excellent electrocatalytic activity towards bromate reduction with significant reduction of overpotential. In amperometric determination of bromate, the calibration plot was linear over the concentration range of 5 Â 10 À5 to 1.2 Â 10 À3 M with a sensitivity of 3.6 mA mM À1. Furthermore, PLL-GA-SiMo film electrode showed fast response and good stability. [39]. In many cases, heteropolyanion immobilized in a polymer matrix is efficient towards electrocatalytic reactions than the homogeneously dissolved one. Hence, these systems are especially interesting for sensor applications. KeywordsIn the present investigation, silicomolybdate-doped-glutaraldehyde-cross-linked poly-l-lysine film modified electrodes are prepared by electrostatically binding the negatively charged SiMo 12 O 4À 40 (SiMo) mediator into positively charged PLL-GA coatings, and its application in the electrocatalytic reduction of bromate is studied. The SiMo-doped-PLL-GA modified electrode showed electrocatalytic activity towards bromate reduction and also served as an electrochemical sensing platform for sensitive amperometric determination of bromate. Thus, PLL-GA-SiMo film electrode has great potentiality in sensor development.As silicomolybdate anion is unstable in neutral and basic aqueous solution and undergoes a series of hydrolysis process [40], studies are carried out in 0.1 M H 2 SO 4 solution. Figure 1 illustrates the incorporation of SiMo 12 molecules

Electrochemical properties of the [SiW10O36(M2O2Kemmegne‐Mbouguen1, Floquet2, Cadot3 2021Comptes Rendus. Chimie6000View full textAdd to dashboardCite

“…The plot of peak (I) current versus scan rates is shown in the inset of Figure 6(B). The peak currents show a linear dependence with scan rates up to 80 mV•s −1 , suggesting that the redox process is surface confined and that the charge transport in the film is fast [66,67].…”

Electrocatalytic Reduction and Determination of Iodate and Periodate at Silicomolybdate‐Incorporated‐Glutaraldehyde‐ Cross‐Linked Poly‐L‐lysine Film Electrodes

“…Among these approaches, entrapment of POMs into polymer matrix is considered as an attractive methodology for sensor fabrication due to simplicity and stability. Recently, we have demonstrated the potentiality of silicomolybdate-entrapped glutaraldehyde-cross-linked poly-llysine (PLL-GA-SiMo) coatings for sensor applications [19,20]. The present study is an extension of [19,20], where we have described preparation and electrochemical characterization of SiMo-doped-PLL-GA film modified electrode in detail.…”

“…Recently, we have demonstrated the potentiality of silicomolybdate-entrapped glutaraldehyde-cross-linked poly-llysine (PLL-GA-SiMo) coatings for sensor applications [19,20]. The present study is an extension of [19,20], where we have described preparation and electrochemical characterization of SiMo-doped-PLL-GA film modified electrode in detail. Here, the electrocatalytic behavior and analytical application of PLL-GA-SiMo film electrodes toward iodate and periodate are investigated.…”

“…Curve d of Figure 1A shows cyclic voltammetric response of SiMo-doped-PLL-GA film modified electrode in pure 0.1 M H 2 SO 4 . As can be seen, three sets of redox peaks were observed in the potential range þ 0.6 to À 0.2 V corresponding to reduction and oxidation of SiMo 12 O 40 4À anion through two-, four-, and six-electron processes, respectively [19,20]. Upon addition of 0.1 mM KIO 3 , there was a dramatic enhancement in the cathodic current of first peak, while second and third peaks remained unchanged as illustrated by curve c. The results suggested that iodate is reduced electrocatalytically by the two-electron reduced species of SiMo 12 O 40 4À anion.…”

“…As a final step, the stability of SiMo-doped-PLL-GA film modified electrode was checked in pure 0.1 M H 2 SO 4 by performing 50 successive cyclic voltammograms. The modified electrode shows relatively stable response and peak height and peak potential of the SiMo redox couples immobilized in PLL-GA film remains nearly unchanged [19,20]. When the modified electrode was cycled 25 times continuously in 0.1 M H 2 SO 4 solution containing 0.1 mM KIO 3 , the decrease in current response was negligible (results not shown).…”