An electrochemical sensor for sub-attomolar determination of aluminum ion with an ultra-wide response range

In this work, an electrochemical sensor was developed for ultra-sensitive determination of aluminum ion (Al 3+ ) using poly(3-aminophenylboronic acid)-gold nanoparticles (PAPBA-AuNPs) modified electrode. The proposed PAPBA-AuNPs modified electrode was prepared by two steps including electrodeposition of gold chloride hydrate and electropolymerization of 3-aminophenylboronic acid. The peak current for PAPBA reduction was recorded by square-wave voltammetry and employed for electrochemical determination of Al 3+ based on the coordination reaction between them. With the increasing concentration of Al 3+ , the peak current for PAPBA reduction diminished. Under the optimized conditions, the proposed electrochemical sensor exhibited a wide response range of 0.10 aM to 10.00 μM and a low limit of detection of 0.019 aM, which is much superior to those of conventional methods. Moreover, this electrochemical sensor was successfully used for Al 3+ detection in tap water and instant noodle samples.