Electrochemically triggered sensing and recovery of mercury over sodium alginate grafted polyaniline

Abstract

An efficient potential triggering process has been established over chemically functionalized sodium alginate grafted polyaniline (SA-g-PANI) under optimum conditions to enable the sensing and extraction of residual mercury ions present in wastewater and soil samples. The observed sensing and extraction parameters were a sensing range of 1.0 nM to 1000 μM, sensitivity of 0.25 mV μM⁻¹ cm⁻², response time of 55 s, recovery time of 15 s, limit of detection of 0.33 nM, and a stability of 60 d, along with 78% extraction after the application of an optimized external potential on the sensing electrode. Furthermore, the sensing and extraction mechanism is explained on the basis of the developed induced potential that occurs after the electrochemical surface interaction between Hg²⁺ and the SA-g-PANI based electrode, along with the repeatability and scale-up possibilities.