Single-Walled Carbon Nanotubes (SWCNTs) as Solid-Contact in All-Solid-State Perchlorate ISEs: Applications to Fireworks and Propellants Analysis

Herein, we present reliable, robust, stable, and cost-effective solid-contact ion-selective electrodes (ISEs) for perchlorate determination. Single-walled carbon nanotubes (SWCNTs) were used as solid-contact material and indium (III) 5, 10, 15, 20-(tetraphenyl) porphyrin chloride (In(III)-porph) as an ion carrier. The sensor exhibited an improved sensitivity towards ClO(4)(−) ions with anionic slope of −56.0 ± 1.1 (R(2) = 0.9998) mV/decade over a linear range 1.07 × 10(−6) – 1.0 × 10(−2) M and detection limit of 1.8 × 10(−7) M. The short-term potential stability and the double-layer capacitance were measured by chronopotentiometric and electrochemical impedance spectroscopy (EIS) measurements, respectively. The sensor is used for ClO(4)(−) determination in fireworks and propellant powders. The results fairly agree with data obtained by ion chromatography.