Facile low-tech potentiometric approach for 2, 4-dichlorophenoxyacetic acid detection down to decamolar level in groundwater
摘要
A robust solid-contact ion-selective electrode was fabricated using carbon cloth as the solid support for the potentiometric detection of 2, 4-dichlorophenoxyacetic acid (2, 4-D). Owing to its excellent electrical conductivity, mechanical strength, and ease of handling, carbon cloth provided a durable and maintenance-free platform for sensor construction. A molecularly imprinted polymer (MIP) specific to 2, 4-D was incorporated as the ionophore within the sensing membrane to ensure high selectivity. The morphological features of MIP and non-imprinted polymer were characterized using FESEM, while the successful removal of the template molecule was confirmed through FTIR and EDX analyses. The developed potentiometric sensor exhibited a Nernstian response of − 28.3 ± 0.35 mV and − 60.6 ± 0.89 mV per decade over two linear concentration ranges (1 × 10−9 M–1 × 10−4 M and 1 × 10−4 M–1 × 10−2 M), with an exceptional detection limit of 1 × 10−10 M. Operating effectively within a pH range of 9.6–10.2, the sensor demonstrated high sensitivity, selectivity, stability, and reusability, along with a rapid response time of 2 min. These features make the proposed MIP-based carbon cloth electrode a promising candidate for on-site and in-field monitoring of 2, 4-D in groundwater.