title: CO2-Responsive Polymer-Functionalized Au Nanoparticles for CO2 Sensor.
abstract: Metallic nanoparticles (NPs) coated with stimuli-responsive polymers (SRPs) exhibit tunable optical properties responding to external stimuli and show promising sensing applications. We present a new CO2-responsive polymer, poly(N-(3-amidino)-aniline) (PNAAN), coated gold NPs (AuNPs) synthesized by directly reducing HAuCl4 with a CO2-responsive monomer N-(3-amidino)-aniline (NAAN). The amidine group of PNAAN can be protonated into a hydrophilic amidinium group by dissolved CO2 (dCO2). This induces the PNAAN to swell and detach from the AuNP surface, resulting in AuNP aggregation and color change. By monitoring the UV absorbance change of AuNPs, a sensitive dCO2 sensor with a linear range of 0.0132 to 0.1584 hPa and a limit of detection (LOD) of 0.0024 hPa is developed. This method shows dramatic improvement in sensitivity and convenience of sample preparation compared with the previously reported dCO2 sensor.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , 10 Kent Ridge Crescent, Singapore 119260.
authors.forename: Ying
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , 10 Kent Ridge Crescent, Singapore 119260.
authors.forename: Kittithat
authors.initials: K
authors.lastname: Promthaveepong
authors.affiliation: Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457.
authors.forename: Nan
authors.initials: N
authors.lastname: Li