Green, in situ fabrication of silver/poly(3-aminophenyl boronic acid)/sodium alginate nanogel and hydrogen peroxide sensing capacity

Abstract

The silver/poly(3-aminophenyl boronic acid)/sodium alginate nanogel (Ag@PABA-SA) was fabricated through green, in situ chemical oxidative polymerization method. 3-Aminophenyl boronic acid (APBA) served as the room temperature reductant of AgNO₃ which acted as an oxidant towards the polymerization of APBA to its conducting polymeric form (PABA). Importantly with SA present, PABA will bind to hydroxyl groups of SA through covalent bonding to generate PABA-SA semi-interpenetrating network, on which AgNPs were concomitantly deposited. This results highly stable, dispersed polymer based AgNPs. The morphology, size, surface charge, composition and thermal stability of nanogel was characterized by UV-vis, Raman and FTIR spectroscopy, TEM, FESEM, EDX, XRD, DLS and zeta potential analysis, TGA and DTG. The Ag@PABA-SA nanogel was investigated as colorimetric probe towards H₂O₂ detection. Wide linearity from 5 to 1000 μM H₂O₂, with low limit of detection of 1.0 μM in addition to satisfactory precision (< 3.5 %) and recovery (95-105 %) and high selectivity was achieved.

Keywords: Alginate; Hydrogel; Hydrogen peroxide; Nanoparticles; PABA; Water.