Introducing an innovative immobilized optode based on PVC-ETH-5294 matrix for environmentally friendly sensing of lead ions

Abstract

A novel selective membrane optode was prepared to determine of ultra-trace amounts of lead. This state-of-the-art optode amalgamates a bespoke ionophore, 4-(thiazol-2-yldiazenyl)benzene-1,3-diol (TDBD), with ETH-5294, assuming the role of a chromoionophore. This potent composition converges with sodium tetraphenylborate (NaTPB) and dioctyl phthalate (DOP), harmoniously enclosed within a matrix of poly(vinyl chloride) (PVC). The influence of various parameters on the preparation of the optode and the determination of Pb²⁺ was investigated and optimized. Evidently, the optode unfurls an expansive linear dynamic expanse, spanning an astonishing range from 6.0 × 10⁻⁹ to 8 × 10⁻⁵ M. Remarkably, it retains an astonishingly low degree of detection and quantification, registering at 1.75 and 5.85 × 10⁻⁹ M, respectively. The response time of the optode was 4.0 min. The optodes versatility extends its embrace towards rejuvenation, permitting multiple rounds of service via 0.2 M HNO₃ solutions. The effect of potential interference ions on the Pb²⁺ determination was illustrated. The results showed that the prepared optode was very selective to lead ions so that it had no significant response to common ions such as Mg²⁺, Mn²⁺, Cd²⁺, Ni²⁺, Fe²⁺, Fe³⁺, Hg²⁺, Cu²⁺, and Co²⁺. The optode was applied successfully to determine of Pb²⁺ indifferent food, biological and environmental samples and result obtained is comparable to atomic absorption spectrometry method.