(92e) Highly Selective Biosensor Based on Ionic Liquids-Assisted Colorimetric Sensing for Arsenite

We present a highly selective biosensor based on colorimetric detection with ionic liquids (ILs). The agglomeration of gold nanoparticles (AuNPs) caused by ionic liquids was prevented by arsenite (As(III)). This study looked at six distinct ILs, including 1-(3-cyanopropyl)-3-methylimidazolium chloride (CPMI), 1-(3-cyanopropyl)pyridinium chloride (CPP), tetradecyldimethylbenzylammonium chloride (TDDBA), cetylpyridinium chloride monohydrate (CP), 1-butyl-1-methylpyrrolidinium methyl carbonate (BMP), and (TBMP). We discovered that a series of ILs were up to 40,000 times more efficient than standard inorganic electrolytes (e.g. NaCl) in producing AuNP aggregation, which was blocked by As (III). Molecular geometry optimization and density functional theory (DFT) calculations were used to investigate two- and three-way non-covalent interactions between ILs, citrate, and metal ions. Arsenite may be distinguished from arsenate and a variety of other ions such as cadmium, zinc, sodium, chromate, bromide, and iodide by inhibiting ILs-induced AuNPs aggregation. The findings of DFT calculations explain why BMP were only binding to arsenite. Repeatability, interference, stability, selectivity, and sensitivity were studied. Detection limits were further lowered by a random DNAzyme substrate. The limit of detection (LOD) of the sensors was 10 ppb. The arsenite sensing was demonstrated using real water samples and validated with inductively coupled plasma-optical emission spectroscopy (ICP-OES).