Detection of Heavy Metal Ions with Ion Imprinting Microfiber Sensor Arrays

In this work, a novel micro/nanofiber sensor array with high sensitivity and good selectivity was demonstrated to simultaneously detect Cr ³⁺ and Ni ²⁺ . The high sensitivity was caused by the evanescent field around a microfiber taper waist region. The specific recognition was achieved using an ion-imprinted polymer coating. The experimental results demonstrated a high sensitivity of 0.01086 nm/nM for Cr ³⁺ , with a linear response in the range of 10-100 nM and a limit of detection (LOD) as low as 0.67174 nM. The sensor array was highly selective and able to distinguish Cr ³⁺ and Ni ²⁺ , even at a high concentration of interfering ions (1 μM). Additionally, the practicability of our proposed sensor array for the simultaneous detection of Cr ³⁺ and Ni ²⁺ in industrial wastewater samples was evaluated, and it achieved simultaneous ppb level detection for Cr ³⁺ and Ni ²⁺ in wastewater. This investigation will facilitate heavy metal ion (HMI) trace detection in the field of drinking water.