Electrochemical detection of picomolar-level fluoride ions using a one-step electrodeposited gold nanoparticle-poly(2-aminophenylboronic acid) modified electrode

An electrochemical sensor was fabricated via a one-step electrodeposition method. • An ultra-wide response range (1.00 × 10 −12  M to 1.00 × 10 −4  M) was obtained. • An ultra-low detection limit (2.14 × 10 −13  M) was achieved. • This sensor was simple, highly selective and practical. A gold nanoparticle-poly(2-aminophenylboronic acid) composite modified gold electrode (AuNPs-poly(2-APBA)/Au) was fabricated for the first time by electrodeposition, which achieved the measurement of picomolar-level fluoride ions (F − ). Using potassium ferricyanide (K 3 Fe(CN) 6 ) as the redox probe, the specific binding of F − to the boronic acid groups in poly(2-APBA) generated negatively charged complexes, which hindered the electron transfer of K 3 Fe(CN) 6 on the electrode surface. Quantitative analysis of F − was realized by monitoring the decline in the K 3 Fe(CN) 6 reduction peak current. The sensor exhibited an ultra-wide response range (1.00 × 10 −12 to 1.00 × 10 −4  M), an ultra-low limit of detection (2.14 × 10 −13  M) and limit of quantification (5.35 × 10 −12  M) with good robustness, precision, ruggedness, and shelf life, and high selectivity. This sensor demonstrated significant advantages in fabrication simplicity, detection sensitivity, response range, and practical applicability, which could be successfully applied to determine F − in Agrocybe aegerita , shrimp and tap water samples, providing an efficient and sensitive analytical method for food safety assessment and environmental monitoring. Download: Download high-res image (137KB) Download: Download full-size image