Bismuth/hydroxyapatite-modified carbon screen-printed electrode for heavy-metal ion detection in aqueous media

Aamir Amanat Ali Khan,Huma Ajab,Asim Yaqub,Mohd Azmuddin Abdullah,A Cardenas Tristan,R Fitria Putri,E Haryono,D Rahmawati Hizbaro,J Tetuko Sri Sumantyo,E Wulanmei

doi:10.1051/e3sconf/20197602001

Abstract

Square-wave voltammetric stripping analysis is attractive for environmental monitoring and trace metal ion determination. The sensitivity is a result of analytes preconcentration steps on the electrode and advanced measurement procedures, where metal analytes are stripped away from the electrode at appropriate potential scan. Screen-printed electrode (SPE) has great advantages for in situ assays of heavy metal ions. Modification of SPE with bismuth (Bi) film improves the amalgamation of metal ions and the addition of hydroxyapatite (HA) increases the ion sorption, and enhances the current response due to the large porous structure and surface active sites for the metal ion binding. The ionization of the functional groups on the electrode surface upon contact with the aqueous system further assists the cation binding. The analytical performance of Bi and HA-modified SPE for simultaneous detection of Cd(II) and Pb(II) ions by square wave anodic stripping voltammetry (SWASV) was evaluated. Under the optimized electrochemical working conditions, calibration graph is linear for 240 s deposition time, in 0.1 M acetate buffer at pH 7.6 with the detection limit of 16.8 ppb for Pb(II). Two peaks corresponding to Cd(II) at -0.8 V and Pb(II) at -0.6 V can be discerned suggesting that Bi-HA modification had increased the current responses.

Highlights

IntroductionHeavy metals are non-biodegradable and follow a cycle in the environment which include water (surface, ground, precipitation), air (particulate matter), soil (bottom sediment) and biosphere (plants, animals, fish, human)
Heavy metals are non-biodegradable and follow a cycle in the environment which include water, air, soil and biosphere
We have recently reported the Limit of Detection (LOD) and Limit of Quantification (LOQ) of the carbon-modified electrode based on cellulose-HA composite which achieves 0.11 ppb LOD and 0.36 LOQ for trace Pb(II) ion detection in blood serum [3434]

Summary

Introduction

Heavy metals are non-biodegradable and follow a cycle in the environment which include water (surface, ground, precipitation), air (particulate matter), soil (bottom sediment) and biosphere (plants, animals, fish, human). Among the priority heavy metal pollutants are lead, cadmium, and mercury [1]. These may be retained indefinitely in the eco-systems and food chain. Lead accumulation has harmful effects on soil microflora and crop growth which will eventually affect the food safety [2]. Lead exposure has caused numerous health effects such as lifelessness, tetchiness, reduced attention span and memory loss, and decreased glutathione in red blood cells which may lead to hallucination, convulsions, paralysis, coma and death [3,4]. Excessive cadmium can lead to hypertension, immuno-suppression, emphysema, kidney failure, bone demineralization, neurotoxicity and induce cancer [5,6]

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