Fabrication of a Fluorophore/Liquid‐Crystal‐Based Oligopeptide Biosensor for the Detection of Cu (II) Ions

Abstract

AbstractA new sensing methodology has been developed for the detection of Cu(II) ions in water by using biotinylated oligopeptide as a probe whereas liquid crystal (LC) and fluorophore were used as signal reporters. The multidentate oligopeptide ligand was used to investigate Cu(II) as a model metal ion. The alkyl terminal group of the coated dimethyl octadecyl [3‐(trimethoxysilyl) propyl] ammonium chloride (DMOAP) was first activated to aldehydic functional group by UV irridiation for 50 seconds. The activated aldehydic functional group was covalent linked with biotinylated oligopeptide via thiolation reaction. As fabricated oligopeptide probe spotted with metal ions was incubated for 30 minutes and followed by tagging with streptavidin‐cyanine‐3 as a fluorophore. Polarized optical microscopy (POM) and fluorescence microarray scanner (FMS) were used as characterization techniques. The developed sensing methodology results were reproducible for different concentrations of model Cu (II) ions as confirmed from the characterization techniques. Our methodology highlighted the detection of Cu(II) ions in water as low as 100 nM, and is the lowest concentration so far reported.