Molecular imprinting of cellulose cotton fabric/silica materials with a colorimetric dithizone chelation for smartphone‐based detection of Zn (II) ions in water samples

Abstract

Molecularly imprinted materials based on imprinting of dithizone‐Zn (II) complexes (DTZ‐Zn (II)) on the cotton fabric/silica, and Color Grab application for OPPO A54 were proposed and applied for the first time to detect Zn (II) ions in water samples. The proposed materials were prepared by using cotton fabrics as cellulosic materials, tetraethoxysilane (TEOS) as silica sources, and DTZ‐Zn (II) as template molecules. The initial concentration of DTZ and Zn (II), volume of TEOS and reaction time were optimized to obtain the maximum adsorption of the DTZ‐Zn (II) complexes in the imprinted materials. The concentrations of HCl and extraction time were optimized to obtain the maximum Zn (II) removal. The results were found that a 10 mL of a solution containing DTZ (0.20 mM) and Zn (II) (0.30 mM), a 25 μL of TEOS, and 10 min of reaction time exhibited the strong binding of template complexes. Zn (II) ions were selectively removed from the materials by using 0.1 M HCl for 10 min. The morphology of the prepared materials was characterized by SEM‐EDS and ATR‐FTIR spectroscopy. The smartphone based the cotton fabric/silica materials exhibited linear relationship between saturation (%) and Zn (II) concentrations in the range of 0.1 to 1.0 mg/L, with limit of detection (LOD) of 0.02 mg/L and limit of quantification (LOQ) of 0.06 mg/L. The proposed method was successfully applied to determine Zn (II) in real water samples with the % recovery ranging from 98‐115 and the acceptable relative standard deviation less than 6 (n =3).This article is protected by copyright. All rights reserved.