Bismuth Film Microelectrode Modified with Overoxidized Poly‐1‐Naphtylamine Protective Membrane for Enhanced Stripping Voltammetric Detection

Abstract

The application of protective overoxidized poly-1-naphtylamine membrane (ONAP) is demonstrated in combination with bismuth film microelectrode (ONAP-BiFME) for anodic stripping voltammetric measurement of trace heavy metals in the presence of some selected surfactants. The ONAP membrane was electrochemically deposited on the surface of bare single carbon fiber microelectrode followed by the in situ or ex situ preparation of the bismuth film. The key operational parameters influencing the stripping performance of the ONAP-BiFME were optimized and its electroanalytical performance was examined in the model solution containing Cd(II) and Pb(II) as test metal ions. The ONAP-BiFME exhibited significantly enhanced stripping voltammetric response (approximately 70% for Cd(II) and 45% for Pb(II)) in comparison with unmodified BiFME in the absence of surfactants. In the presence of high concentrations, e.g., 20 mg L À1, of anionic or cationic surfactants, the stripping signal for, e.g., Cd(II) decreased for less than 6% at the ONAP-BiFME, whereas at the unmodified BiFME the signal attenuated considerably (approximately 38%). Moreover, in the presence of 10 mg L À1 of nonionic surfactant Triton X-100, the stripping signals at the bare BiFME were almost completely suppressed, whereas at the ONAP-BiFME exhibited linear concentration behavior in the examined concentration range from 10 to 120 mg L À1 , with the calculated limit of detection of 5.0 mg L À1 and 3.4 mg L À1 for Cd(II) and Pb(II), respectively in connection with 60 s accumulation time. The attractive behavior of ONAPmodified BiFME expands the applicability of bismuth-based electrodes for measurement of trace heavy metals in real environments, where the presence of more complex matrix can be expected.

A Decade with Bismuth‐Based Electrodes in Electroanalysis

“…Such protective layers have been shown to improve signal-to-noise ratios and afford the electrode additional protection against fouling which can be troublesome in more complex analytical matrices [14,38,87]. Recently however, more complex modifications have also been applied to offer additional mechanical stability and improve the sensitivity of the sensor including sophisticated polymer film composites [99,128,129,139], a nanotube incorporated Nafion coating [151] and a carbon nanotubechelating agent nanocomposite [174]. As varied as the BiE configurations themselves have been the electrochemical techniques utilized for the sensing.…”

“…Similarly popular (room-temperature) ionic liquids, (RT)ILs [128,157], had also been shown useful as specific modifiers, enabling improvements to the surface characteristics of a BiFE via enhanced conductivity [128] or to attain the desired extraction capabilities [157]. Finally, such new materials were also electrogenerated poly-alkyl/aryl-amine films [129,153] applicable to intimately coating the BiFE for protection against surfactants and other highly adhesive molecules [129], and achieving markedly enhanced sensitivity for the target ions [153].…”

“…New or innovated methods for the triad of Zn(II), Cd(II) and Pb(II) had included their determination in model solutions [129,130,146,148,157,161], natural (often river) [137, 139, 145, 153 -156], tap [134,135,139,143,151,159], and industrial waste waters [128,134,141], white wine [139], soil extracts [141,154], synthetic fertilizer [145], vegetables [160,163], medicinal herbs [162], or even in whole blood [133]. Other metal and metalloid species included Tl(I) ion and its determination in the presence of EDTA [149], Fe(III) in seawater [136], Co(II) and /or Ni(II) in river and spiked waters [140,152], or As(III) in river and seawater specimens [158].…”

Electrochemical fabrication of metallic nanostructured electrodes for electroanalytical applications

“…Among these heavy metals much attention is paid to the detection of lead, 99,140,141 cadmium, 140,141 mercury, 142 arsenic 143,144 and chromium. 24,144,145 The most common strategy for sensing these metals is by anodic stripping voltammetry at electrodeposited bismuth films (as shown in Fig.…”

The effect of acetate concentration, solution pH and conductivity on the anodic stripping voltammetry of lead and cadmium ions at in situ bismuth-plated carbon microelectrodes

“…It has since been followed by a significant number of publications on Bi-coated microelectrodes (see for example [25][26][27][28][29][30][31][32][33][34]). …”