King Mongkuts Institute of Technology Ladkrabang; King Mongkuts Institute of Technology Ladkrabang; Ramkhamhaeng University; National Science & Technology Development Agency - Thailand; National Nanotechnology Center (NANOTEC); Mahidol University; Mahidol University
Type
Article
Source Title
ANALYTICAL SCIENCES
ISSN
0910-6340
Year
2016
Volume
32
Issue
7
Page
769-773
Open Access
gold
Publisher
JAPAN SOC ANALYTICAL CHEMISTRY
Format
PDF
Abstract
A simple and rapid method was developed for the detection of poly(diallyldimethylammonium chloride) (PDADMAC) using citrate-capped silver nanoparticles (AgNPs). Detection was based on anti-aggregation of AgNPs in phosphate buffer caused by PDADMAC. Due to its positive charges, PDADMAC was adsorbed onto AgNPs via electrostatic interaction with citrate, which resulted in the charges at the particle surfaces to become positive and caused repulsion among particles. Furthermore, long-chain PDADMAC provided steric hindrance. These two effects promoted the dispersion of AgNPs in the phosphate buffer. A change in the state of dispersion influenced the surface plasmon resonance (SPR) of AgNPs. Therefore, in this work, the concentration of PDADMAC was determined by monitoring changes in absorbance (at 396 nm) caused by SPR of AgNPs. Under optimal conditions, the calibration was linear over the range of 1 to 100 mg L-1 with a detection limit of 0.7 mg L-1. Satisfactory precision was obtained (RSD = 2.8%). This method was successfully applied to the determination of PDADMAC in tap water samples. The recoveries ranged from 86.0 - 107.5%.
