High Sensitive Surface Plasmon Resonance (SPR) Sensor Based on Modified Calix(4)arene Self Assembled Monolayer for Cadmium Ions Detection

Abstract

In this work, a new chromogenic calix(4)arene was functionalized onto self assembled monolayer (SAM) of cysteamine for cadmium ions detection and tested by using SPR measurement. The functionalization of modified SPR sensor is based on the oxidation of calixarene-SAM alcohol group to quinone. Four interfering ions were used Cu²⁺, Co²⁺, Mg²⁺ and Ca²⁺. pH of sensor in which the sensitivity of sensor is higher was optimized for cadmium ions and detection of ions was made in basic solution. Detection limit reached for Cd²⁺ is lower than 10⁻¹¹ M with a dynamic response time of about 16 s when changing from 10⁻⁶ M cadmium to 10⁻⁵ M.