Detection of hidden drugs with a molecularly imprinted electrochemiluminescence sensor

Abstract

A new strategy for the fabrication of an electroluminescence sensor was proposed based on the incorporation of electroluminescence (ECL) detection and the molecular imprinting technology (MIT). The sensor fabrication consisted of two steps, the first one was the immobilization of the light emitting material Ru(bpy)₃²⁺ on a GC electrode with the well-established Nafion/the multi-wall carbon nanotube (MWCNT) composite film method and the second step involves re-modification of the Ru(bpy)₃²⁺/Nafion/MWCNT electrode with a thin film of molecularly imprinted sol–gel polymers with methamphetamine (MA) as the template molecules. The as-prepared sensor exhibited a very high sensitivity and excellent selectivity toward the target molecule MA. A detection limit as low as 4.0 × 10⁻¹⁵ M was achieved for MA with a wide calibration range from 1.0 × 10⁻¹⁰ to 1.0 × 10⁻¹⁴ M. The high sensitivity of the sensor allowed the drugs in a closed container to be detected by their odors.